As-worded it would count cards with multiple keywords multiple times. Probably fine in commander what with requiring board commitment with all the boardwipes likely being thrown about, but seems pretty strong in any 20-life format.
I have mixed feelings about spark. Only being able to activate one ability per turn gives it bad synergy with itself, which means that rather than creating a single deck archetype it will instead come to define whatever format it's in. The high value of running just a few so that they don't need to compete with each other means that every competitive deck will want to run a few of them. Though, the minus abilities do help with this somewhat by creating payoffs for playing a higher number of the cards.
Also energy counters ran into issues due to not being interactive enough. Spark has a similar feel to it.
But despite any concerns, it is a really cool mechanic. You can make a lot of neat designs with it and I particularly like how it captures the fantasy of wizards, clerics, shamans, and other stereotypical 'squishy caster' archetypes in that they get both smaller cantrips and bigger but more expensive options.
Fire Flinger 2R
Creature - Goblin Wizard
Spark
+1: Target creature gains menace until end of turn.
-2: ~ deals 2 damage to any target.
2/3
Vessel of Divinity 3W
Artifact - Equipment
Spark
+1: Equip ~ to target creature you control.
+1: Put a +1/+1 counter on equipped creature.
-3: Equipped creature gets +3/+3 and gains flying, vigilance, and lifelink until end of turn.
Tidal Mastery 2U
Enchantment
Spark
-1: Tap target creature. It doesn't untap during its controller's next untap step.
+2: Return up to one target tapped creature to its owner's hand and sacrifice ~.
Yeah adding white to that probably makes it kosher.
See: World Queller for white sacrifice effects. Or, even more appropriately, Doom Foretold.
My only gripe is with the ransom mechanic itself. I feel like it should somehow benefit the person who ransomed the permanent, like a real-life ransom.
Maybe a card to fix that...
Ransom CollectorWB
Creature - Thrull
Whenever a ransom is paid, create a treasure token.
2/2
Thrull seems to fit because the whole mechanic feels very Orzhov to me. Ransom is also a really cool sort of Whitemane Lion effect for your own creatures.
Virtuous Lender1W
Creature - Human Noble
Flash
When ~ enters the battlefield, ransom another creature you own.
1/3
Indebted Angel2WBB
Creature - Angel
Flying, vigilance
If ~ would die, ransom it instead. No making ends meet, no means to an end.
4/4
There's a lot of other fun stuff you can do with ransom...
Grave Cost1B
Sorcery
Ransom any number of target creature cards from your graveyard (Those cards are exiled. You may pay 3 at any time to return one to your hand). Open coffers open coffins.
Surveyor's Scope is a good anti-manascrew card in multiplayer, as it can actually put you ahead by a land. Works well with fetchlands since you can activate it in response to the fetch.
You said you gave bad stats to any creature with duel, but the +1/+1 counters encourage them to use the ability whenever possible, and therefore encourages opponents to just not play any small creatures to avoid giving you the duel counters. Duel punishes small creatures above and beyond just killing them. There are plenty of cards that punish small creatures in Magic, such as Rakdos Charm, Batwing Brume, or Massacre Wurm, but it's not a good idea to make it into a keyword mechanic since that warps the whole format into not just killing small creatures, but punishing them by advancing the other player's board state.
What you basically have is a stronger Prodigal Pyromancer or Blood Cultist, and even in morerecentdesigns these sorts of cards can never easily remove creatures above 1 toughness without support from some other card (Irencrag Pyro need a separate card draw effect, Spikeshot Elder needs an aura or equipment, and Tracker needs another bigger creature). Cards that can repeatedly remove creatures by themselves tend to cost a lot of mana, like Hateflayer or Avatar of Woe.
The mechanic cost should show the final cost, and be an alternative cost.
ex.
Blazing Touch 3R
Invert 4RR (You may pay this spell's invert cost instead of its mana cost when you cast this spell. If you do, resolve its effects in reverse order).
I agree with this.
Further, there's a weird issue with it in that the first 'effect' of the card is technically invert's effect. So you get a paradox where if the inversion happens first then you've already done it wrong by not going backwards, while if the inversion happens last then you don't invert anything until you get to that effect.
But given that it's a keyword you could just word it properly to account for that. Such as "If you paid (amount), the rest of this card's effects happen in reverse order."
In general it seems intuitive enough that I don't think it'd be an issue in actual gameplay. However, the design space for this is also fairly limited if you're trying to create effects that couldn't be conventional kicker costs.
Blazing Touch3R
Sorcery (R)
Invert 1R: (You may pay an additional 1R When you cast this spell. If you do, resolve the last effect on this card prior to the first).
Blazing Touch deals 2 damage to target creature and 2 damage to that creature’s controller.
If a red source you control would deal damage this turn it deals that much damage plus two instead.
kicker version
Blazing Touch3R
Sorcery (R)
Kicker: 1R (You may pay an additional 1R as you cast this spell.)
Blazing Touch deals 2 damage to target creature and 2 damage to that creature’s controller. If it was kicked, it deals 4 damage to that creature and that player instead.
If another red source you control would deal damage this turn it deals that much damage plus two instead.
Boneyard Militia3B
Creature - Skeleton Soldier (R)
Invert B: (You may pay an additional B When you cast this spell. If you do, resolve the last effect on this card prior to the first).
When Boneyard Militia enters the battlefield it deals damage equal to the number of skeletons you control to target player.
When Boneyard Militia enters the battlefield create three 1/1 black skeleton tokens.
1/1
So, this one actually is already freely reversible. If more than one trigger would happen at once, you decide what order they go onto the stack. Invert doesn't actually do anything here.
But a hypothetical sorcery version might go...
Boneyard Militia2B
Sorcery (R)
Kicker: B (You may pay an additional B as you cast this spell.)
Boneyard Militia deals damage equal to the number of skeletons you control to target player. If it was kicked, it deals that much damage plus 3 instead.
Create three 1/1 black skeleton creature tokens.
Inspired Rejection3UU
Instant (R)
Invert U: (You may pay an additional 1U When you cast this spell. If you do, resolve the last effect on this card prior to the first).
Counter up to one target spell if its converted mana cost is less than the number of cards in your hand.
Draw two cards.
kicker version
Inspired Rejection3UU
Instant (R)
Kicker: U (You may pay an additional U as you cast this spell.)
If ~ was kicked, draw two cards. Otherwise, draw two cards at the beginning of the next end step.
Counter up to one target spell if its converted mana cost is less than the number of cards in your hand.
Really only that last one is any different as a result of using kicker over invert. And even then, only a little bit.
Jester's Boots are probably fine just because of how much they cost. However the second ability would probably end up causing an annoying amount of searching and shuffling.
Terraforming Automaton is busted in Tron and similar land-focused decks. It should also be "exile a land you control" to avoid the trick of targeting a fetchland and then sacrificing it in response.
Duel is basically targeted removal. There's not really a reason why you wouldn't use it, even before the part about getting +1/+1 counters for using it. The counters just create the odd situation where you're better off not playing blockers just so they have nothing to duel.
Pestilence, First Horseman of the Apocalypse 2G
Legendary Creature - Horseman-of-the-Apocalypse
Infect
Hexproof
When this creature enters the battlefield, search your library for a card named "War, Second Horseman of the Apocalypse" and put it in your hand, then shuffle the library.
1/3
Hexproof feels a bit off-theme; you might try Deathtouch instead, to make blocking a trickier prospect. Overall it feels fine.
War, Second Horseman of the Apocalypse 3R
Legendary Creature - Horseman-of-the-Apocalypse
First Strike, Trample
If you cast this spell when a creature you control dealt combat damage last turn, it also has haste.
When this creature enters the battlefield, search your library for a card named "Famine, Third Horseman of the Apocalypse" and put it in your hand, then shuffle the library.
3/1
Just give it haste, honestly. No reason for the 'dealt combat damage last turn' oddness. (plus, technically 'last turn' would be an opponent's turn). Feels fine otherwise
Famine, Third Horseman of the Apocalypse 4U
Legendary Creature - Horseman-of-the-Apocalypse
When this creature enters the battlefield, your opponent must sacrifice a nonland permanent they control and discard a card, then you search your library for a card named "Death, Fourth Horseman of the Apocalypse" and put that card in your hand. Afterwards, shuffle your library.
3/3
This isn't blue. It could bounce those permanents back to hand, but blue can't generally cause things to be sacrificed. You could phrase it similarly to Pendrell Mists, i.e. "When ~ enter the battlefield, for each non-knight creature, its controller sacrifices it unless they pay 1.
However I will point out that even that, and other cards like Reality Acid or Rishadan Footpad are outdated and not good references. Words of Wind or Curfew are better templates for this sort of thing.
Death, Fourth Horseman of the Apocalypse 5B
Legendary Creature - Horseman-of-the-Apocalypse
At the beginning of your upkeep, destroy target permanent opponent controls. This bypasses Hexproof.
3/3
Black can't destroy enchantments. This should probably just say 'creatures'. Also I would argue against it randomly ignoring hexproof. Compare: Avatar of Woe. Bypassing things that prevent the thing you're doing is a touchy subject.
Rise of the Apocalypse 3GRUB
Sorcery
You may only cast this spell if you have "Pestilence, First Horseman of the Apocalypse", "War, Second Horseman of the Apocalypse", "Famine, Third Horseman of the Apocalypse", and "Death, Fourth Horseman of the Apocalypse" on the battlefield tapped and attacking.
You win the game. This cannot be prevented.
This spell cannot be countered and exiled.
As a sorcery you aren't able to cast this during your combat step, when the horsemen would typically be 'tapped and attacking'. Otherwise I would say the condition for this is fine. If an opponent lets you build up four creatures on the board and then swing with all four, then you deserve the win.
"This cannot be prevented" should probably be removed. Firstly, that doesn't have a clear rules meaning since no cards "prevent" winning, they simply say you "can't" win. There's a difference. Second, again, bypassing things that prevent the thing you're doing is a touchy subject. Cards that prevent opponents from winning are rare and splashy. It feels bad to be punished for going through the effort to cast one.
"This spell cannot be countered" is probably fine, however, since unlike "can't win" effects, there are many counterspells at every mana cost. Plus, there's already counterplay in the form of removing literally any of the horsemen before they can all attack and this spell resolves. The additional "and exiled" part is dangerous territory though simply because there are manyreasons a card might be exiled aside from just effects like Mindbreak Trap.
Thinking more on it, this sort of chicanery could actually see print if a whole cycle of command-swappers were printed as part of a set. Because in that case there would be enough cards to justify making the new rulings, just like partner justified new rulings about how commander tax and damage work.
e.g.
Boros Legend WR
Legendary Creature - Pegasus Soldier
First Strike, Haste
Whenever ~ attacks, you may transfer command to another nontoken attacking creature you own.
3/1
Simic Legend 1UG
Legendary Creature - Lizard Wizard UG, T: Put a +1/+1 counter on target creature.
Whenever a +1/+1 counter is placed on a nontoken creature you own, you may transfer command to that creature.
2/3
Neat Artifact 4
Artifact 1, T: Transfer command to target nontoken legendary creature you own.
and so on.
So I think the best implementation would be to just say...
"WUR, T: Transfer command to target nontoken creature you own. That creature gains this ability for as long as it is your commander."
And then define what "transfer command" means separately from the card so that you can handle edge-cases and so on without gumming up the card itself with words and rulings.
At that point, I think the only remaining issues I can think of is when you get ambiguity from having multiples of a creature like with the Seven Dwarves, or else when an effect causes something like a basic land to become a creature. Some of the rules for commander sort of rely on the assumption that your commander is visibly distinct from other cards in the deck, but strictly speaking it still works if they aren't. It's just potentially confusing.
Player A has Volrath as commander. He steals player B's Usbrelus.
Player A activate Usbrelus, targeting his own... idk, mossbridge troll? Or another random creature player B owns.
Mossbridge Troll becomes the new player A's commander
Why you say it doesn't work?
Well with the original wording it would presumably result in player A having two commanders (Voltrath and the troll) and player B having none. This is because, despite the reminder text, the rules of the game say that it is in fact possible to have multiple commanders. The new wording works though, at least in this regard.
However the new commander still loses the ability to transfer its command when it changes zones. Abilities given to a creature are 'forgotten' when a card changes zones and becomes a new game object. Commander-ness is an exception to this, but the granted ability isn't. Also it's unclear what happens when a token becomes your commander, since tokens normally disappear when they change zones and are not represented in game terms by a physical card (even though for simplicity you might physically put a card on the table to represent them), and commander-ness is tied to a physical card.
And once more: reminder text is not rules text. You would need to spell out in rules text that the new physical card that is your commander has no 'memory' of any prior occasion where that same physical card was your commander if that's your intent. Because forgetting prior actions as your commander is not the default assumption of the format (there is in fact no assumption that changing commanders mid-game is possible at all), and a card that runs contrary to the rules needs to clarify what happens as a result. You could also do that through house rulings which the reminder text references, but then you need to be sure your new house rulings aren't going to break the game or run contrary to any existing rules. A card requiring its own house rules is generally a bad sign when it comes to card design.
Even if you're cool with that and your group is cool with that then you still need to spell out those new rules ahead of time to avoid making up rules mid-game from a position of bias. Unless maybe your group is really just into some Calvinball-type stuff where deciding after blocks that since you gave your deathtouch creature another instance of deathtouch it should now instantly kill players.
That actually sound crazy and fun just for commander!
It's not just an unusual and wacky circumstance, it flat out doesn't function within the rules. You literally have to house-rule the outcome. The ability to determine with certainty the outcome of any interaction of two cards is one of the greatest strengths of Magic.
If you and your friends enjoy that sort of wackiness and can all get along with that stuff happening then sure, just go for it. No need to ask for advice from this forum.
But as a design for an actual card that sort of mentality doesn't work. It creates arguments and ambiguous gameplay if you're playing with people you don't know. So my advice as someone who isn't part of your local playgroup is to go with something that works within the rules.
Also worth noting: his own ability would also be required to target Flagbearers, which may or may not be intentional.
Why so? Only opponents have to choose flagbearers
Fair point. I missed that part.
Still, that's reminder text, not rules text. It has no effect on the game. As-worded all the ability does is put a flag counter on a creature and changes their creature type to Flagbearer. Nothing else. If you want him to have an effect like you're describing then there's a simple and rules-supported way to achieve something similar, and that's to simply put it on a static ability the same as the old cards do it.
"While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able."
Or alternatively, if you want the effect to persist after your commander leaves the field...
T: put a flag counter on target creature (you control?). As long as that creature has a flag counter on it, it is a Flagbearer in addition to its other types and has "While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able."
That way it's pretty much equivalent to putting a Coalition Flag on something and there's no doesn't-actually-work rules weirdness.
As a side note, being able to effectively blank spot removal as a tap ability with no cost is kinda crazy. But he is a 5-drop with unremarkable stats, so, 'eh'.
Quite a few issues, rules-wise...
The reminder text is plainly wrong because partners are a thing. As-worded the ability the creature gains to then hand off commander-ness to other creatures goes away when it changes zones. Also both commander damage and commander tax are established to be connected to the individual physical card.
That last one gets you into weird situations like whether a creature who becomes your commander, hits someone, stops being your commander, dies, comes back, then becomes your commander again, then hits the same person again also counts its prior commander damage. It can also lead to weirdness if you, say, make one of the Seven Dwarves your commander, since that obfuscates which one is your commander.
Perhaps the trickiest complication: your opponent could gain control of Usbrelus and use his ability. Then they would presumably transfer his commander-ness to one of their own creatures, which is all sorts of messy.
Overall I would say lessen the scope of this ability. Maybe change it to "1W, T: Put a lieutenant counter on target creature you own." and then separately "If ~ is your commander, combat damage dealt by creatures you own with a lieutenant counter counts as commander damage dealt by ~."
or something along those lines.
As an additional note, a three-color creature with a utility ability that doesn't affect the battlefield or generate card advantage should be a lot stronger by current creature design. I would say a 3/4 Vigilance, Hexproof, Haste would be fine regardless of which version you use. (Hexproof in this case is fine because he's not a value engine creature.)
Regarding Giorgiliano: creature types, which 'Flagbearer' currently is, no longer have inherent rules. Spells and abilities being required to target Flagbearers would need to be spelled out as an ability either on Giorgiliano or given to the target creature as part of the ability.
Also worth noting: his own ability would also be required to target Flagbearers, which may or may not be intentional.
Extra turns are so busted in 2HG that even Savor the Moment becomes great - a draw and a land drop for both you and your partner, and can effectively give non-Medomai creatures haste if they weren't able to attack the previous turn. Not to mention any upkeep/end step triggers and so on.
My only criticism would be that Medomai probably isn't the most efficient way to get extra turns. Running Grand Arbiter Augustin IV and replacing all the cards you're using to protect and enable Medomai with more control and extra turn stuff would probably be the truly competitive choice. Or potentially both of you could play mono-U and run things like High Tide, Extraplanar Lens (with snow lands), and Gauntlet of Power.
If you want to get meta you could play something like Kaalia of the Vast in a deck that contains no angels, demons, or dragons.
Effectively a vanilla 2/2 flyer for 4 that draws tremendous hate to you from the very start of the game in a way that none of the 'worthless' commanders ever will.
Otherwise any bad monowhite commander probably has a leg up just on account of monowhite being an infamously bad commander color relative to the sultai colors.
Though untap effects are pretty much always going to go infinite, and costing 8 makes that somewhat more reasonable.
Also energy counters ran into issues due to not being interactive enough. Spark has a similar feel to it.
But despite any concerns, it is a really cool mechanic. You can make a lot of neat designs with it and I particularly like how it captures the fantasy of wizards, clerics, shamans, and other stereotypical 'squishy caster' archetypes in that they get both smaller cantrips and bigger but more expensive options.
Fire Flinger 2R
Creature - Goblin Wizard
Spark
+1: Target creature gains menace until end of turn.
-2: ~ deals 2 damage to any target.
2/3
Vessel of Divinity 3W
Artifact - Equipment
Spark
+1: Equip ~ to target creature you control.
+1: Put a +1/+1 counter on equipped creature.
-3: Equipped creature gets +3/+3 and gains flying, vigilance, and lifelink until end of turn.
Tidal Mastery 2U
Enchantment
Spark
-1: Tap target creature. It doesn't untap during its controller's next untap step.
+2: Return up to one target tapped creature to its owner's hand and sacrifice ~.
See: World Queller for white sacrifice effects. Or, even more appropriately, Doom Foretold.
My only gripe is with the ransom mechanic itself. I feel like it should somehow benefit the person who ransomed the permanent, like a real-life ransom.
Maybe a card to fix that...
Ransom Collector WB
Creature - Thrull
Whenever a ransom is paid, create a treasure token.
2/2
Thrull seems to fit because the whole mechanic feels very Orzhov to me. Ransom is also a really cool sort of Whitemane Lion effect for your own creatures.
Virtuous Lender 1W
Creature - Human Noble
Flash
When ~ enters the battlefield, ransom another creature you own.
1/3
Indebted Angel 2WBB
Creature - Angel
Flying, vigilance
If ~ would die, ransom it instead.
No making ends meet, no means to an end.
4/4
There's a lot of other fun stuff you can do with ransom...
Grave Cost 1B
Sorcery
Ransom any number of target creature cards from your graveyard (Those cards are exiled. You may pay 3 at any time to return one to your hand).
Open coffers open coffins.
Definitely my favorite mechanic of the bunch.
Howling Mine, Dictate of Kruphix, Font of Mythos, Kami of the Crescent Moon, and so on can help out. Any effect which lets the player whose turn it is draw an extra card benefits from extra turns. Temple Bell and similar are less good since they also give opponents cards for your own extra turns.
Surveyor's Scope is a good anti-manascrew card in multiplayer, as it can actually put you ahead by a land. Works well with fetchlands since you can activate it in response to the fetch.
You said you gave bad stats to any creature with duel, but the +1/+1 counters encourage them to use the ability whenever possible, and therefore encourages opponents to just not play any small creatures to avoid giving you the duel counters. Duel punishes small creatures above and beyond just killing them. There are plenty of cards that punish small creatures in Magic, such as Rakdos Charm, Batwing Brume, or Massacre Wurm, but it's not a good idea to make it into a keyword mechanic since that warps the whole format into not just killing small creatures, but punishing them by advancing the other player's board state.
What you basically have is a stronger Prodigal Pyromancer or Blood Cultist, and even in more recent designs these sorts of cards can never easily remove creatures above 1 toughness without support from some other card (Irencrag Pyro need a separate card draw effect, Spikeshot Elder needs an aura or equipment, and Tracker needs another bigger creature). Cards that can repeatedly remove creatures by themselves tend to cost a lot of mana, like Hateflayer or Avatar of Woe.
Further, there's a weird issue with it in that the first 'effect' of the card is technically invert's effect. So you get a paradox where if the inversion happens first then you've already done it wrong by not going backwards, while if the inversion happens last then you don't invert anything until you get to that effect.
But given that it's a keyword you could just word it properly to account for that. Such as "If you paid (amount), the rest of this card's effects happen in reverse order."
In general it seems intuitive enough that I don't think it'd be an issue in actual gameplay. However, the design space for this is also fairly limited if you're trying to create effects that couldn't be conventional kicker costs.
kicker version
Blazing Touch 3R
Sorcery (R)
Kicker: 1R (You may pay an additional 1R as you cast this spell.)
Blazing Touch deals 2 damage to target creature and 2 damage to that creature’s controller. If it was kicked, it deals 4 damage to that creature and that player instead.
If another red source you control would deal damage this turn it deals that much damage plus two instead.
So, this one actually is already freely reversible. If more than one trigger would happen at once, you decide what order they go onto the stack. Invert doesn't actually do anything here.
But a hypothetical sorcery version might go...
Boneyard Militia 2B
Sorcery (R)
Kicker: B (You may pay an additional B as you cast this spell.)
Boneyard Militia deals damage equal to the number of skeletons you control to target player. If it was kicked, it deals that much damage plus 3 instead.
Create three 1/1 black skeleton creature tokens.
kicker version
Inspired Rejection 3UU
Instant (R)
Kicker: U (You may pay an additional U as you cast this spell.)
If ~ was kicked, draw two cards. Otherwise, draw two cards at the beginning of the next end step.
Counter up to one target spell if its converted mana cost is less than the number of cards in your hand.
Really only that last one is any different as a result of using kicker over invert. And even then, only a little bit.
Terraforming Automaton is busted in Tron and similar land-focused decks. It should also be "exile a land you control" to avoid the trick of targeting a fetchland and then sacrificing it in response.
Duel is basically targeted removal. There's not really a reason why you wouldn't use it, even before the part about getting +1/+1 counters for using it. The counters just create the odd situation where you're better off not playing blockers just so they have nothing to duel.
There are also minor wording issues on all three.
Hexproof feels a bit off-theme; you might try Deathtouch instead, to make blocking a trickier prospect. Overall it feels fine.
Just give it haste, honestly. No reason for the 'dealt combat damage last turn' oddness. (plus, technically 'last turn' would be an opponent's turn). Feels fine otherwise
This isn't blue. It could bounce those permanents back to hand, but blue can't generally cause things to be sacrificed. You could phrase it similarly to Pendrell Mists, i.e. "When ~ enter the battlefield, for each non-knight creature, its controller sacrifices it unless they pay 1.
However I will point out that even that, and other cards like Reality Acid or Rishadan Footpad are outdated and not good references. Words of Wind or Curfew are better templates for this sort of thing.
Black can't destroy enchantments. This should probably just say 'creatures'. Also I would argue against it randomly ignoring hexproof. Compare: Avatar of Woe. Bypassing things that prevent the thing you're doing is a touchy subject.
As a sorcery you aren't able to cast this during your combat step, when the horsemen would typically be 'tapped and attacking'. Otherwise I would say the condition for this is fine. If an opponent lets you build up four creatures on the board and then swing with all four, then you deserve the win.
"This cannot be prevented" should probably be removed. Firstly, that doesn't have a clear rules meaning since no cards "prevent" winning, they simply say you "can't" win. There's a difference. Second, again, bypassing things that prevent the thing you're doing is a touchy subject. Cards that prevent opponents from winning are rare and splashy. It feels bad to be punished for going through the effort to cast one.
"This spell cannot be countered" is probably fine, however, since unlike "can't win" effects, there are many counterspells at every mana cost. Plus, there's already counterplay in the form of removing literally any of the horsemen before they can all attack and this spell resolves. The additional "and exiled" part is dangerous territory though simply because there are many reasons a card might be exiled aside from just effects like Mindbreak Trap.
e.g.
Boros Legend WR
Legendary Creature - Pegasus Soldier
First Strike, Haste
Whenever ~ attacks, you may transfer command to another nontoken attacking creature you own.
3/1
Simic Legend 1UG
Legendary Creature - Lizard Wizard
UG, T: Put a +1/+1 counter on target creature.
Whenever a +1/+1 counter is placed on a nontoken creature you own, you may transfer command to that creature.
2/3
Neat Artifact 4
Artifact
1, T: Transfer command to target nontoken legendary creature you own.
and so on.
So I think the best implementation would be to just say...
"WUR, T: Transfer command to target nontoken creature you own. That creature gains this ability for as long as it is your commander."
And then define what "transfer command" means separately from the card so that you can handle edge-cases and so on without gumming up the card itself with words and rulings.
At that point, I think the only remaining issues I can think of is when you get ambiguity from having multiples of a creature like with the Seven Dwarves, or else when an effect causes something like a basic land to become a creature. Some of the rules for commander sort of rely on the assumption that your commander is visibly distinct from other cards in the deck, but strictly speaking it still works if they aren't. It's just potentially confusing.
However the new commander still loses the ability to transfer its command when it changes zones. Abilities given to a creature are 'forgotten' when a card changes zones and becomes a new game object. Commander-ness is an exception to this, but the granted ability isn't. Also it's unclear what happens when a token becomes your commander, since tokens normally disappear when they change zones and are not represented in game terms by a physical card (even though for simplicity you might physically put a card on the table to represent them), and commander-ness is tied to a physical card.
And once more: reminder text is not rules text. You would need to spell out in rules text that the new physical card that is your commander has no 'memory' of any prior occasion where that same physical card was your commander if that's your intent. Because forgetting prior actions as your commander is not the default assumption of the format (there is in fact no assumption that changing commanders mid-game is possible at all), and a card that runs contrary to the rules needs to clarify what happens as a result. You could also do that through house rulings which the reminder text references, but then you need to be sure your new house rulings aren't going to break the game or run contrary to any existing rules. A card requiring its own house rules is generally a bad sign when it comes to card design.
Even if you're cool with that and your group is cool with that then you still need to spell out those new rules ahead of time to avoid making up rules mid-game from a position of bias. Unless maybe your group is really just into some Calvinball-type stuff where deciding after blocks that since you gave your deathtouch creature another instance of deathtouch it should now instantly kill players.
If you and your friends enjoy that sort of wackiness and can all get along with that stuff happening then sure, just go for it. No need to ask for advice from this forum.
But as a design for an actual card that sort of mentality doesn't work. It creates arguments and ambiguous gameplay if you're playing with people you don't know. So my advice as someone who isn't part of your local playgroup is to go with something that works within the rules.
Fair point. I missed that part.
Still, that's reminder text, not rules text. It has no effect on the game. As-worded all the ability does is put a flag counter on a creature and changes their creature type to Flagbearer. Nothing else. If you want him to have an effect like you're describing then there's a simple and rules-supported way to achieve something similar, and that's to simply put it on a static ability the same as the old cards do it.
"While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able."
Or alternatively, if you want the effect to persist after your commander leaves the field...
T: put a flag counter on target creature (you control?). As long as that creature has a flag counter on it, it is a Flagbearer in addition to its other types and has "While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able."
That way it's pretty much equivalent to putting a Coalition Flag on something and there's no doesn't-actually-work rules weirdness.
As a side note, being able to effectively blank spot removal as a tap ability with no cost is kinda crazy. But he is a 5-drop with unremarkable stats, so, 'eh'.
The reminder text is plainly wrong because partners are a thing. As-worded the ability the creature gains to then hand off commander-ness to other creatures goes away when it changes zones. Also both commander damage and commander tax are established to be connected to the individual physical card.
That last one gets you into weird situations like whether a creature who becomes your commander, hits someone, stops being your commander, dies, comes back, then becomes your commander again, then hits the same person again also counts its prior commander damage. It can also lead to weirdness if you, say, make one of the Seven Dwarves your commander, since that obfuscates which one is your commander.
Perhaps the trickiest complication: your opponent could gain control of Usbrelus and use his ability. Then they would presumably transfer his commander-ness to one of their own creatures, which is all sorts of messy.
Overall I would say lessen the scope of this ability. Maybe change it to "1W, T: Put a lieutenant counter on target creature you own." and then separately "If ~ is your commander, combat damage dealt by creatures you own with a lieutenant counter counts as commander damage dealt by ~."
or something along those lines.
As an additional note, a three-color creature with a utility ability that doesn't affect the battlefield or generate card advantage should be a lot stronger by current creature design. I would say a 3/4 Vigilance, Hexproof, Haste would be fine regardless of which version you use. (Hexproof in this case is fine because he's not a value engine creature.)
Regarding Giorgiliano: creature types, which 'Flagbearer' currently is, no longer have inherent rules. Spells and abilities being required to target Flagbearers would need to be spelled out as an ability either on Giorgiliano or given to the target creature as part of the ability.
Also worth noting: his own ability would also be required to target Flagbearers, which may or may not be intentional.
My only criticism would be that Medomai probably isn't the most efficient way to get extra turns. Running Grand Arbiter Augustin IV and replacing all the cards you're using to protect and enable Medomai with more control and extra turn stuff would probably be the truly competitive choice. Or potentially both of you could play mono-U and run things like High Tide, Extraplanar Lens (with snow lands), and Gauntlet of Power.
Venser, Shaper Savant and Teferi, Mage of Zhalfir could be a particularly intimidating pair. Or just double-Augustin to stack up the taxes. Erayo, Soratami Ascendant is infamously busted in 2HG if she isn't banned.
Effectively a vanilla 2/2 flyer for 4 that draws tremendous hate to you from the very start of the game in a way that none of the 'worthless' commanders ever will.
Otherwise any bad monowhite commander probably has a leg up just on account of monowhite being an infamously bad commander color relative to the sultai colors.