How many games with Yawgmoth do you have under your belt in a semi-competitive and above EDH environment?
About 15. All my games are semi-competitive and above, because I play with the kind of people who would sooner get a cheap proxy of an original dual land than play a Tarkir triple land. The kind of people who spend hours calculating the chances of each possible hand. You know when people post in this forum lamenting that their LGS was taken over by insufferable tryhards who suck the fun out of the game? Yeah, that's the people I play with.
And as a lover of all things black, I've played all manners of commanders that had black in their color identity, including most of the mono black commanders discussed here so far, and yes, I've done so at this kind of table. And on the basis of this experience I reiterate my argument: that Yawgmoth performs a lot better than his mono-black ilk when faced with 75% decks, and can even hold his own in the face of more powerful. cEDH-level decks (mostly by making use of Contamination, the one card black has to slow down the more powerful decks). That said, the gulf in power between him and commanders with more favorable color identities was evident: I've actually tried him in the 99 of various Sultai and Abzan decks, and the couple times I actually drew into him he proved a game changer, accomplishing a lot more than he was doing by himself... Which brings me back to the one thing I've been repeating in this whole topic: that his abilities are both powerful and capable of impacting any table, even ones with cEDH-level decks, but he's held back by the fact that his color by itself is just not good enough.
You seem bent on winning this crusade about the evil ToT who dared to say that Yawgmoth is a great competitive commander... But I never said that. All I said is that he's stronger than his mono-black ilk and that he's very good in 75% environments while still being able to hold his own in more competitive environments. HOLD HIS OWN, not OMG THIS IS THE BEST COMMANDER EVER HE WINS EVERY GAME PLAY THIS DECK NEW META or whatever youtubers say in the titles of their videos.
It is a fact that a deck headed by Yawgmoth can do anything a deck headed by any other mono-black commander can do, and that he can do things those other guys cannot do: this simple fact makes it easier for him to win games, which in turn makes him better than the other mono-black commanders, simply because he offers you more. Is this "more" he offers enough to dominate the competitive meta, or even to do great/good in it? Of course not, because mono-black is still an inferior color identity, and the lack of ways to stop enemy combos mans that your sole realistic chance of winning against optimized, cEDH-viable combo decks is to pray to get your own combo before they do... Which, thanks to the good things a deck like this has to offer, you might SOMETIMES be able to pull off. And "sometimes" is still better than "absolutely never".
Imagine an italian guy ranking 47th in a chess world cup, with the other italian players being placed much lower: is that guy a world-class player and a tournament winner? Absolutely not. But he's still the best among the italian players. That's kind of my argument in regards to Yawgmoth: I never claimed that he was a top-tier competitive pick, but still it's a fact that, in an environment where all mono-black decks perform poorly, he performs a bit better than his ilk, which makes him the best of his ilk. If this offends you to the point of starting a crusade over it, it's frankly not my problem.
It seems to me that the issue here is that you and I have a very different definition of the word "viable". I could write an entire essay on the topic of the "top tier fallacy" (long story short, the definition most people have of what constitutes a "top tier" is based on a textbook case of circular logic), but it seems to me that such a debate would derail this topic even more than it already has.
OP has asked a question. I have provided my answer, and you've provided yours: I have no interest in changing mine, and it seems to me that the same goes to you, so this conversation is over. OP will try some things based on our answers and see for themselves who they agree with.
1) Depends on the situation. Unlike in cEDH (where the only creatures that matter are mana dorks and combo pieces), in 75% there are plenty of targets to take care of, depending on the kind of deck the opponent is using. And I specifically stated that line about killing creatures was only relevant for 75%, NOT for 100% cEDH.
2) You answered your own question further down in your post. Black also has access to a plethora of other options for fueling Yawgmoth which are, however, quite inefficient. I did mention that being one of the main issues with mono black, but it is a problem that lies in the color identity, not in the abilities of the card.
3) He's decent because he enables combos, meaning that combos involving him require one less tutor to be found, given that one of the pieces is in your command zone. And black is the best color for tutoring to begin with, so assembling one of those combos is going to be reasonably easy, albeit not as fast as the guys you mentioned for mono blue/green (simply because blue has better draw/utility, and green has faster mana ramp: that's just how the color pi works). As for the lack of meaningful interaction I'm sorry, I thought at some point a guy by the name of GloriousGoose had mentioned interaction not being as important when you're just trying to power out a combo as fast as possible? I was working under that same assumption. Besides, the lack of interaction beyond killing creatures is a problem shared by all black decks, so we're back to my original point: that Yawgmoth's weakness lies in his color identity, not in his ability.
4) On Sidisi: again, she either faces the same issues as Yawgmoth, or she's literally a command zone tutor. Which don't get me wrong, is decently cool, but if all you want to do is tutor up Ad Nauseam then you might as well pay literally any other commander, put all existing tutors in your deck, and mulligan until you open with one in your hand. Many tutors available to black are actually cheaper than Sidisi, letting you go off one turn earlier.
5) On Xiahou: does he really combo out "more efficiently" than Yawgmoth? The latter can actively contribute to your search for combo pieces by drawing you cards. Do not underestimate the ability to draw at instant speed for no mana cost. Xiahou cannot consistently give you that utility and combo potential unti his engine is online, while Yawgmoth can, in a pinch, help you draw into his own engine. The only counter-argument to this is pointing out, once again, that supplying fuel for Yawgmoth's ability to draw us cards is not that easy, and can in fact be as problematic as Xiahou's own need for an engine in order to function... And thus we're once again back to my original point: that what really holds back this card is its color identity, rather than its abilities.
6) On Chainer: his loop-enabling activated ability costs mana, Yawgmoth's doesn't. Again, do not underestimate the power of an instant-speed sac outlet/draw engine with no mana cost.
7) On Erebos: his activated ability also costs mana... And as you said, he's all about finding an use for "surplus" resources. I thought we had agreed that our goal in cEDH was to combo off BEFORE getting to the point where we'd even have "surplus" resources?
Mine was a simple consideration based on a simple fact: in cEDH you win via combo, and a combo is easier/faster to assemble if one of its key pieces is sitting in your command zone, because that essentially means that one less tutor is necessary in order to win. Now, Yawgomth is a sac outlet that needs Mikaeus in order to explode, and Mikaeus needs a sac outlet in order to explode, so you could run one or the other in the command zone and the rest of the 99 would remain essentially the same... And since Mikaeus also has the option of pulling a 2-cards combo with Triskelion, one could argue that Mikaeus is actually superior to Yawgmoth as a commander. And while that would be a fair point, I still maintain that using Mikaeus in the 99 is better for two reasons: firstly, going Buried Alive+Victimize is a far more efficient way of putting Mikaeus and Triskelion on the field, compared to casting them, and secondly I once again must reiterate that Yawgmoth's ability to draw cards makes him automatically better not only because he actually has something to do before the combo is assembled (as opposed to Xiahou/Mikaeus, who will just sit in the command zone until their respective engines are online), but especially because he can actually HELP you actively search for the pieces you still need. In a card game, no actions is more powerful or more important than drawing cards.
That is, of course, provided that we can actually keep Yawgmoth supplied with creatures to sac, which in mono black is not the easiest thing to do compared to bicolor or tricolor decks... And thus we're back to my original point, once again: Yawgmoth's main issue lies in his color identity, it lies in the fact that his color of choice is not the best when it comes to supporting his own gimmick. Compare to Urza: his gimmick is artifacts, and blue IS the best color for supporting artifacts, so it's much easier for a mono blue Urza deck to be effective in cEDH, compared to a mono black Yawgmoth deck. But this doesn't change the fact that Yawgmoth's abilities as printed are in themselves more powerful than those seen on any other mono black commander so far: they draw you cards, enable infinite combos AND provide a potential alternate wincon. No other mono black commander can claim to have all three these aspects rolled into its abilities: Sidisi doesn't enable combos (she merely searches them), Xiahou doesn't draw cards, Chainer cannot actively set up his own combos and also costs mana to use, Erebos is not a combo piece, neither is Razaketh, the Foulblooded, Mikaeus doesn't contribute anything to the deck until it's time to come into play and get the combo going, Volrath and Drana are voltron finishers (which is arguably a lesser way of winning in cEDH), and so on so forth.
Yawgmoth's abilities do 3 things. This is a fact. No other mono black commander has abilities that do 3 things. This is also a fact. Theses 3 things Yawgmoth's abilities do cannot glue a deck together and get it to explode as quickly or as efficiently as the abilities of other commanders of other colors, simply because those other commanders are better supported by their respective color identities: this is also a fact, but the problem lies in the color identity, not in the abilities themselves.
I therefore repeat: Yawgmoth is as competitive as a mono black deck is ever going to be. Which means decently competitive, but not as competitive as other, better, color identities.
First of all yeah, my mistake: when I said Yawgmoth is as competitive as a monocolored deck can be, I meant a mono BLACK deck. That said, to answer this question: not as fast as those other guys, that's for sure. But he's still an instant-speed sac outlet with no mana cost, so there ARE things you can do with him: with Mike and Filigree Familiar/Peace Strider you can draw your entire deck, and then you can drop something like Ichor Rats and proliferate everyone to death. It takes a lot of mana to pull off, but black does have plenty of big mana options. Alternatively, since the idea is to use the ETB of fox/strider to gain life so as to offset Yawgmoth's life cost, you could use Sanguine Bond as a finisher for that combo, which overall costs a hell of a lot less mana to pull off: the issue in this case is running out of cards to draw before the enemy runs out of life. Heck, fox/strider are going to gain you so much life that Aetherflux Reservoir could MAYBE be a viable finisher.
So yeah, in a 75% environment where creatures are still relevant, Yawgmoth is exceptional on the account of being able to kill enemy creatures while drawing you cards to set up a combo like the one I mentioned above. And in a full 100% cEDH environment Yawgmoth is still decent, but he cannot match the speed and efficiency of those blue and green combo commanders you mentioned: given that his main gimmick cannot be fueled as efficiently in mono black, I dare say that's the most you can expect a mono black commander to do. Thus I repeat: Yawgmoth is the best mono black commander, and is as competitive as a mono black deck is going to be... Which, sadly, means not as much as other color identities are capable of
EDIT: I SOMEHOW forgot the most obvious solution... Gray Merchant of Asphodel. Yawgmoth + Mike + Gray Merchant should be the easiest and most efficient way of winning, because even if you control no other black permanents you're still looking at a minimum of 7 damage to all opponents per iteration of the combo, which should be enough to kill everyone before you run out of cards to draw.
1) Nevi Disk is cast and is therefore on the stack
2) Glen Elendra is activated, and thus goes on the stack: it dying is a cost paid as part of making it go on the stack
3) That death, which I remind you was a cost, causes Glissa's trigger to go on the stack
So that's the order in which all these things go on the stack, and remember, the stack resolves in reverse order. So Glissa resolves first (with the other two still on the stack), then Glen Elendra resolves countering Nevi Disk, and then Nevi Disk ends up in the gravyard, not having resolved as a result of being countered. As such, when Glissa resolves Nevi Disk is still on the stack, and is therefore NOT a valid target for her.
Urza, Yisan, Teferi and Selvala are all decks made great by the fact that their playstyle allows them to circumvent the inherent problem of their color identity. Like, they still suffer from lack of diverse answers to enemy strategies, but in their case it doesn't matter because they don't care about answering in the first place: they just want to power out a combo as quickly as possible. They all fall under what would be called a "turbo" deck in Yugioh jargon which, yes, makes them more competitive than Yawgmoth, but that doesn't change the fact that Yawgmoth is still as competitive as a mono black is going to be (I.E. not as much as those other guys you mentioned, but still decent).
As for Sidisi, I frankly don't get why you included her: if you're going to amass recurring creatures for her to exploit, then she's just as clunky as Yawgmoth because, as others mentioned, black by itself is not the best color for consistently providing fodder. And if you're going to sac herself to her own ability, then she's literally a Razaketh's Rite in the command zone: if the goal is doubling up on tutors so as to bring out a combo as quickly as possible, then I'd rather have her in the 99 and a combo piece, such as Mikaeus, the Unhallowed or, yes, Yawgmoth himself as the commander.
He's as competitive as a monocolored deck can be in this format. I call him the best mono-black commander by a mile, but the lack of diverse answers to enemy strategies might hurt. But I really need to reiterate: what I feel holds him back is the color identity, NOT the abilities: those are perfectly viable in even 100% cEDH.
I see your point concerning Force, I'll be trying more carefully to find the perfect balance in quantities of each card.
For now, it seems to me the bnb of this deck is turn 1 land Visions, turn 2 land pass, in enemy turn counter/bounce something, turn 3 drop Narset, turn 4 resolve Day's Undoing and then people quit. I find that the most dangerous decks are those capable of putting out so many creatures we cannot reliably bounce/counter them all, thus preventing us from creating safe conditions for Narset to come in. Burn and Affinity seem particularly bad from this point of view, while Jund, Dredge/Bridgevine and other such midrange decks with lots of hand control are actually pretty easy to deal with, because Day's Undoing completely murders them. Combo decks like Storm or Urza also seem easy, because we have so much counter-magic we can easily stop them if they luck into their wincon before we luck into ours.
So yeah, my verdict so far is that Burn is this deck's boogeyman, fast aggros are hard match-ups, anything else is actually quite easy.
So, my initial impression upon testing the deck is that we REALLY need Narset out by turn 3 or 4. She single-handedly defines what this deck is. So yeah, I'm currently trying to include as much draw power as possible (full set of Remand, Serum Visions, even considering Opt) in order to dig as deep as possible for her. Perhaps Supreme Will instead of Commit/Memory? And then there's the new Force of Negation: definitely not a budget option, but given how cheap the rest of the game is, investing in one big money card might be worthwhile. The new Force really looks like it could do a lot of work for this deck.
Next:
An intelligent Kracken, DnD style
OR
Partner Commanders
OR
A Commander which makes you the Monarch/ cards about you being the Monarch.
Note:The lack of creature type is intentional.
I choose D: all of the above!
Slarkrethel, Devourer of Kings - 5UUU
Legendary Creature - Kraken
Partner with Ghald, Hand of Slarkrethel
Trample, Islandwalk, Hexproof
When // enters the battlefield, target opponent becomes the monarch.
When // deals combat damage to the monarch, draw that many cards.
8/8
Ghald, Hand of Slarkrethel - 2BB
Legendary Creature - Merfolk Assassin
Partner with Slarkrethel, Devourer of Kings
First Strike, Deathtouch
// can only attack the monarch.
When // deals combat damage to the monarch, they discard that many cards.
3/4
I technically cheated because these are about capitalizing on when YOUR OPPONENT is the monarch, but I mean, dealing damage to the monarch makes you the monarch, so it kinda counts?
Anyway, next: a tribal commander for a tribe that doesn't have one yet!
Well I for one am fascinated by this idea, which would have never occurred to me had I not stumbled upon this topic by complete accident. It also appears to be cheaper than most things you see in Modern today, which is a plus. I'll be giving a try and contribute a bit in the upcoming weeks
I just wanted to stop by and applaud you for your color selection. Great stuff. Concerning the one god you've created, untapping in the end phase of the very turn you put it down could lead to some degenerate stuff, so I recommend having it untap during the untap step of every other player instead, like Seedborn Muse.
Embrace the social aspect of the format, talk to my playgroup and friends, and build casually so that even if combo pieces end up in my deck, I don't rely on them to win the game every time, and use them instead as the ball in the coffin for those few games where things really get bizarre and difficult.
I can respect that. My line however was meant to criticize those in this topic who want to deal with combos with drastic bans.
This shocked me a bit, surely these same players running one shot voltron decks or Craterhoof Behemoth wins wouldn't be that dim to not see how easily an Isochron Scepter win turn 8 achieved the same effect at the same speed?
This was pretty much my argument as well. When faced with 120 HPs protected by all manners of high-end strategies, you cannot just put down a small/medium creature per turn, turn it sideways, and hope it goes through: you need to win in one big fell swoop. And when it comes to winning in one big fell swoop, when it comes to telling the opponent "if this resolves then you're powerless to stop me", I frankly see no difference between an infinite combo, an unkillable voltron, a complete removal of other people's resources (think Mycosynth Lattice + Vandalblast), or Avenger+Craterhoof. So essentially there are two option in front of someone who wants to address the problem of "descent into combo":
1) Ban the combo cards. This is both unfeasible (there are so many different interactions in MtG, that if you were to make it impossible to use the currently popular combos people would simply come up with new one that you cannot even imagine right now) and hypocritical, because it leads to a toxic playstyle being completely eradicated, while two or three other playstyles that are arguably just as toxic remain completely unaddressed.
2) Ban all key cards used in all kinds of toxic decks, making it impossible to win in one big fell swoop. This would be absolutely unfeasible, because it would require you to ban all the voltron cards, all the combo cards, and all the big mana/fast tokens/mass buff cards... And then breaking the board state of decks such as pure stax/pillowfort would become nigh impossible, so those decks would become the next problem and you'd end up needing to ban their key cards too. At the end of the day, this would result in the banning of literally half of the card pool and the gutting of 5 major playstyles out of what, 8? The blow to the game's diversity would be staggering.
So I maintain that this discussion is destined to go nowhere: regardless of whether or not you believe combos are a problem, the fact of the matter is that there's no feasible, realistic solution for it. You can SAY that combos are a problem, but there's nothing you can actually DO about it.
The only two suggestions I've seen in this topic that I actually like are the banning of all "search your library for this or that" cards (because on paper the point of 99 singleton cards is to force the players to choose between the consistency of running one wincon and the versatility of running multiple ones, but if you've got so many tutors to be absolutely certain that your one wincon will be on the field by turn 4/5, than that choice becomes completely meaningless), and the reduction of the starting HP total from 40 to 30 or perhaps even 20 (so as to make attacking with creatures an actually worthwhile wincon even without the likes of Craterhoof). Such changes would keep the high-end competitive players honest, preventing their games from being "ramp tutor ramp tutor ramp tutor ramp tutor I WIN", but at the same time thy wouldn't affect the majority of the playerbase, I.E. the casual players who have a favorite card/interaction/combo and just want to have fun with it: I mean, such players probably weren't going to be able to afford a Vampiric Tutor anyway.
But banning the combos themselves would be hypocritical at best, and actively detrimental for the format's future at worst.
About 15. All my games are semi-competitive and above, because I play with the kind of people who would sooner get a cheap proxy of an original dual land than play a Tarkir triple land. The kind of people who spend hours calculating the chances of each possible hand. You know when people post in this forum lamenting that their LGS was taken over by insufferable tryhards who suck the fun out of the game? Yeah, that's the people I play with.
And as a lover of all things black, I've played all manners of commanders that had black in their color identity, including most of the mono black commanders discussed here so far, and yes, I've done so at this kind of table. And on the basis of this experience I reiterate my argument: that Yawgmoth performs a lot better than his mono-black ilk when faced with 75% decks, and can even hold his own in the face of more powerful. cEDH-level decks (mostly by making use of Contamination, the one card black has to slow down the more powerful decks). That said, the gulf in power between him and commanders with more favorable color identities was evident: I've actually tried him in the 99 of various Sultai and Abzan decks, and the couple times I actually drew into him he proved a game changer, accomplishing a lot more than he was doing by himself... Which brings me back to the one thing I've been repeating in this whole topic: that his abilities are both powerful and capable of impacting any table, even ones with cEDH-level decks, but he's held back by the fact that his color by itself is just not good enough.
You seem bent on winning this crusade about the evil ToT who dared to say that Yawgmoth is a great competitive commander... But I never said that. All I said is that he's stronger than his mono-black ilk and that he's very good in 75% environments while still being able to hold his own in more competitive environments. HOLD HIS OWN, not OMG THIS IS THE BEST COMMANDER EVER HE WINS EVERY GAME PLAY THIS DECK NEW META or whatever youtubers say in the titles of their videos.
It is a fact that a deck headed by Yawgmoth can do anything a deck headed by any other mono-black commander can do, and that he can do things those other guys cannot do: this simple fact makes it easier for him to win games, which in turn makes him better than the other mono-black commanders, simply because he offers you more. Is this "more" he offers enough to dominate the competitive meta, or even to do great/good in it? Of course not, because mono-black is still an inferior color identity, and the lack of ways to stop enemy combos mans that your sole realistic chance of winning against optimized, cEDH-viable combo decks is to pray to get your own combo before they do... Which, thanks to the good things a deck like this has to offer, you might SOMETIMES be able to pull off. And "sometimes" is still better than "absolutely never".
Imagine an italian guy ranking 47th in a chess world cup, with the other italian players being placed much lower: is that guy a world-class player and a tournament winner? Absolutely not. But he's still the best among the italian players. That's kind of my argument in regards to Yawgmoth: I never claimed that he was a top-tier competitive pick, but still it's a fact that, in an environment where all mono-black decks perform poorly, he performs a bit better than his ilk, which makes him the best of his ilk. If this offends you to the point of starting a crusade over it, it's frankly not my problem.
It seems to me that the issue here is that you and I have a very different definition of the word "viable". I could write an entire essay on the topic of the "top tier fallacy" (long story short, the definition most people have of what constitutes a "top tier" is based on a textbook case of circular logic), but it seems to me that such a debate would derail this topic even more than it already has.
OP has asked a question. I have provided my answer, and you've provided yours: I have no interest in changing mine, and it seems to me that the same goes to you, so this conversation is over. OP will try some things based on our answers and see for themselves who they agree with.
2) You answered your own question further down in your post. Black also has access to a plethora of other options for fueling Yawgmoth which are, however, quite inefficient. I did mention that being one of the main issues with mono black, but it is a problem that lies in the color identity, not in the abilities of the card.
3) He's decent because he enables combos, meaning that combos involving him require one less tutor to be found, given that one of the pieces is in your command zone. And black is the best color for tutoring to begin with, so assembling one of those combos is going to be reasonably easy, albeit not as fast as the guys you mentioned for mono blue/green (simply because blue has better draw/utility, and green has faster mana ramp: that's just how the color pi works). As for the lack of meaningful interaction I'm sorry, I thought at some point a guy by the name of GloriousGoose had mentioned interaction not being as important when you're just trying to power out a combo as fast as possible? I was working under that same assumption. Besides, the lack of interaction beyond killing creatures is a problem shared by all black decks, so we're back to my original point: that Yawgmoth's weakness lies in his color identity, not in his ability.
4) On Sidisi: again, she either faces the same issues as Yawgmoth, or she's literally a command zone tutor. Which don't get me wrong, is decently cool, but if all you want to do is tutor up Ad Nauseam then you might as well pay literally any other commander, put all existing tutors in your deck, and mulligan until you open with one in your hand. Many tutors available to black are actually cheaper than Sidisi, letting you go off one turn earlier.
5) On Xiahou: does he really combo out "more efficiently" than Yawgmoth? The latter can actively contribute to your search for combo pieces by drawing you cards. Do not underestimate the ability to draw at instant speed for no mana cost. Xiahou cannot consistently give you that utility and combo potential unti his engine is online, while Yawgmoth can, in a pinch, help you draw into his own engine. The only counter-argument to this is pointing out, once again, that supplying fuel for Yawgmoth's ability to draw us cards is not that easy, and can in fact be as problematic as Xiahou's own need for an engine in order to function... And thus we're once again back to my original point: that what really holds back this card is its color identity, rather than its abilities.
6) On Chainer: his loop-enabling activated ability costs mana, Yawgmoth's doesn't. Again, do not underestimate the power of an instant-speed sac outlet/draw engine with no mana cost.
7) On Erebos: his activated ability also costs mana... And as you said, he's all about finding an use for "surplus" resources. I thought we had agreed that our goal in cEDH was to combo off BEFORE getting to the point where we'd even have "surplus" resources?
Mine was a simple consideration based on a simple fact: in cEDH you win via combo, and a combo is easier/faster to assemble if one of its key pieces is sitting in your command zone, because that essentially means that one less tutor is necessary in order to win. Now, Yawgomth is a sac outlet that needs Mikaeus in order to explode, and Mikaeus needs a sac outlet in order to explode, so you could run one or the other in the command zone and the rest of the 99 would remain essentially the same... And since Mikaeus also has the option of pulling a 2-cards combo with Triskelion, one could argue that Mikaeus is actually superior to Yawgmoth as a commander. And while that would be a fair point, I still maintain that using Mikaeus in the 99 is better for two reasons: firstly, going Buried Alive+Victimize is a far more efficient way of putting Mikaeus and Triskelion on the field, compared to casting them, and secondly I once again must reiterate that Yawgmoth's ability to draw cards makes him automatically better not only because he actually has something to do before the combo is assembled (as opposed to Xiahou/Mikaeus, who will just sit in the command zone until their respective engines are online), but especially because he can actually HELP you actively search for the pieces you still need. In a card game, no actions is more powerful or more important than drawing cards.
That is, of course, provided that we can actually keep Yawgmoth supplied with creatures to sac, which in mono black is not the easiest thing to do compared to bicolor or tricolor decks... And thus we're back to my original point, once again: Yawgmoth's main issue lies in his color identity, it lies in the fact that his color of choice is not the best when it comes to supporting his own gimmick. Compare to Urza: his gimmick is artifacts, and blue IS the best color for supporting artifacts, so it's much easier for a mono blue Urza deck to be effective in cEDH, compared to a mono black Yawgmoth deck. But this doesn't change the fact that Yawgmoth's abilities as printed are in themselves more powerful than those seen on any other mono black commander so far: they draw you cards, enable infinite combos AND provide a potential alternate wincon. No other mono black commander can claim to have all three these aspects rolled into its abilities: Sidisi doesn't enable combos (she merely searches them), Xiahou doesn't draw cards, Chainer cannot actively set up his own combos and also costs mana to use, Erebos is not a combo piece, neither is Razaketh, the Foulblooded, Mikaeus doesn't contribute anything to the deck until it's time to come into play and get the combo going, Volrath and Drana are voltron finishers (which is arguably a lesser way of winning in cEDH), and so on so forth.
Yawgmoth's abilities do 3 things. This is a fact. No other mono black commander has abilities that do 3 things. This is also a fact. Theses 3 things Yawgmoth's abilities do cannot glue a deck together and get it to explode as quickly or as efficiently as the abilities of other commanders of other colors, simply because those other commanders are better supported by their respective color identities: this is also a fact, but the problem lies in the color identity, not in the abilities themselves.
I therefore repeat: Yawgmoth is as competitive as a mono black deck is ever going to be. Which means decently competitive, but not as competitive as other, better, color identities.
First of all yeah, my mistake: when I said Yawgmoth is as competitive as a monocolored deck can be, I meant a mono BLACK deck. That said, to answer this question: not as fast as those other guys, that's for sure. But he's still an instant-speed sac outlet with no mana cost, so there ARE things you can do with him: with Mike and Filigree Familiar/Peace Strider you can draw your entire deck, and then you can drop something like Ichor Rats and proliferate everyone to death. It takes a lot of mana to pull off, but black does have plenty of big mana options. Alternatively, since the idea is to use the ETB of fox/strider to gain life so as to offset Yawgmoth's life cost, you could use Sanguine Bond as a finisher for that combo, which overall costs a hell of a lot less mana to pull off: the issue in this case is running out of cards to draw before the enemy runs out of life. Heck, fox/strider are going to gain you so much life that Aetherflux Reservoir could MAYBE be a viable finisher.
So yeah, in a 75% environment where creatures are still relevant, Yawgmoth is exceptional on the account of being able to kill enemy creatures while drawing you cards to set up a combo like the one I mentioned above. And in a full 100% cEDH environment Yawgmoth is still decent, but he cannot match the speed and efficiency of those blue and green combo commanders you mentioned: given that his main gimmick cannot be fueled as efficiently in mono black, I dare say that's the most you can expect a mono black commander to do. Thus I repeat: Yawgmoth is the best mono black commander, and is as competitive as a mono black deck is going to be... Which, sadly, means not as much as other color identities are capable of
EDIT: I SOMEHOW forgot the most obvious solution... Gray Merchant of Asphodel. Yawgmoth + Mike + Gray Merchant should be the easiest and most efficient way of winning, because even if you control no other black permanents you're still looking at a minimum of 7 damage to all opponents per iteration of the combo, which should be enough to kill everyone before you run out of cards to draw.
1) Nevi Disk is cast and is therefore on the stack
2) Glen Elendra is activated, and thus goes on the stack: it dying is a cost paid as part of making it go on the stack
3) That death, which I remind you was a cost, causes Glissa's trigger to go on the stack
So that's the order in which all these things go on the stack, and remember, the stack resolves in reverse order. So Glissa resolves first (with the other two still on the stack), then Glen Elendra resolves countering Nevi Disk, and then Nevi Disk ends up in the gravyard, not having resolved as a result of being countered. As such, when Glissa resolves Nevi Disk is still on the stack, and is therefore NOT a valid target for her.
Urza, Yisan, Teferi and Selvala are all decks made great by the fact that their playstyle allows them to circumvent the inherent problem of their color identity. Like, they still suffer from lack of diverse answers to enemy strategies, but in their case it doesn't matter because they don't care about answering in the first place: they just want to power out a combo as quickly as possible. They all fall under what would be called a "turbo" deck in Yugioh jargon which, yes, makes them more competitive than Yawgmoth, but that doesn't change the fact that Yawgmoth is still as competitive as a mono black is going to be (I.E. not as much as those other guys you mentioned, but still decent).
As for Sidisi, I frankly don't get why you included her: if you're going to amass recurring creatures for her to exploit, then she's just as clunky as Yawgmoth because, as others mentioned, black by itself is not the best color for consistently providing fodder. And if you're going to sac herself to her own ability, then she's literally a Razaketh's Rite in the command zone: if the goal is doubling up on tutors so as to bring out a combo as quickly as possible, then I'd rather have her in the 99 and a combo piece, such as Mikaeus, the Unhallowed or, yes, Yawgmoth himself as the commander.
For now, it seems to me the bnb of this deck is turn 1 land Visions, turn 2 land pass, in enemy turn counter/bounce something, turn 3 drop Narset, turn 4 resolve Day's Undoing and then people quit. I find that the most dangerous decks are those capable of putting out so many creatures we cannot reliably bounce/counter them all, thus preventing us from creating safe conditions for Narset to come in. Burn and Affinity seem particularly bad from this point of view, while Jund, Dredge/Bridgevine and other such midrange decks with lots of hand control are actually pretty easy to deal with, because Day's Undoing completely murders them. Combo decks like Storm or Urza also seem easy, because we have so much counter-magic we can easily stop them if they luck into their wincon before we luck into ours.
So yeah, my verdict so far is that Burn is this deck's boogeyman, fast aggros are hard match-ups, anything else is actually quite easy.
I choose D: all of the above!
Slarkrethel, Devourer of Kings - 5UUU
Legendary Creature - Kraken
Partner with Ghald, Hand of Slarkrethel
Trample, Islandwalk, Hexproof
When // enters the battlefield, target opponent becomes the monarch.
When // deals combat damage to the monarch, draw that many cards.
8/8
Ghald, Hand of Slarkrethel - 2BB
Legendary Creature - Merfolk Assassin
Partner with Slarkrethel, Devourer of Kings
First Strike, Deathtouch
// can only attack the monarch.
When // deals combat damage to the monarch, they discard that many cards.
3/4
I technically cheated because these are about capitalizing on when YOUR OPPONENT is the monarch, but I mean, dealing damage to the monarch makes you the monarch, so it kinda counts?
Anyway, next: a tribal commander for a tribe that doesn't have one yet!
I can respect that. My line however was meant to criticize those in this topic who want to deal with combos with drastic bans.
This was pretty much my argument as well. When faced with 120 HPs protected by all manners of high-end strategies, you cannot just put down a small/medium creature per turn, turn it sideways, and hope it goes through: you need to win in one big fell swoop. And when it comes to winning in one big fell swoop, when it comes to telling the opponent "if this resolves then you're powerless to stop me", I frankly see no difference between an infinite combo, an unkillable voltron, a complete removal of other people's resources (think Mycosynth Lattice + Vandalblast), or Avenger+Craterhoof. So essentially there are two option in front of someone who wants to address the problem of "descent into combo":
1) Ban the combo cards. This is both unfeasible (there are so many different interactions in MtG, that if you were to make it impossible to use the currently popular combos people would simply come up with new one that you cannot even imagine right now) and hypocritical, because it leads to a toxic playstyle being completely eradicated, while two or three other playstyles that are arguably just as toxic remain completely unaddressed.
2) Ban all key cards used in all kinds of toxic decks, making it impossible to win in one big fell swoop. This would be absolutely unfeasible, because it would require you to ban all the voltron cards, all the combo cards, and all the big mana/fast tokens/mass buff cards... And then breaking the board state of decks such as pure stax/pillowfort would become nigh impossible, so those decks would become the next problem and you'd end up needing to ban their key cards too. At the end of the day, this would result in the banning of literally half of the card pool and the gutting of 5 major playstyles out of what, 8? The blow to the game's diversity would be staggering.
So I maintain that this discussion is destined to go nowhere: regardless of whether or not you believe combos are a problem, the fact of the matter is that there's no feasible, realistic solution for it. You can SAY that combos are a problem, but there's nothing you can actually DO about it.
The only two suggestions I've seen in this topic that I actually like are the banning of all "search your library for this or that" cards (because on paper the point of 99 singleton cards is to force the players to choose between the consistency of running one wincon and the versatility of running multiple ones, but if you've got so many tutors to be absolutely certain that your one wincon will be on the field by turn 4/5, than that choice becomes completely meaningless), and the reduction of the starting HP total from 40 to 30 or perhaps even 20 (so as to make attacking with creatures an actually worthwhile wincon even without the likes of Craterhoof). Such changes would keep the high-end competitive players honest, preventing their games from being "ramp tutor ramp tutor ramp tutor ramp tutor I WIN", but at the same time thy wouldn't affect the majority of the playerbase, I.E. the casual players who have a favorite card/interaction/combo and just want to have fun with it: I mean, such players probably weren't going to be able to afford a Vampiric Tutor anyway.
But banning the combos themselves would be hypocritical at best, and actively detrimental for the format's future at worst.