I love him, and run him in my ~500 unpowered, although I also run Goblin Chieftain, Siege-Gang Commander, Voidmage Prodigy, Captain of the Watch, and a few others.
I like the genjus (Genju of the Spires et. al)--they can be answered with Nature's Claim and Erase (which
should maybe be in as an answer to Rancor anyways).
This format seems like it will be dominated by the one-drop equipment--Trusty Machete et. al. You might want to replace Crush with Shattering Spree or Smelt, or even Vandalblast. 11 seems like a lot of equipment for 180 cards, anyways. But I'd definitely want a Kor Duelist.
I think nightscape familiar (grixis) is the best, mostly as a sapphire medallion, but also in part because it has the best body (regeneration can hold off certain creatures for a while). Sapphire medallion is most useful, I think, simply because of the archetypes that want it (UB control, storm). It's useful in other combinations (the bant one might be playable), but I don't think I'd pick it very highly at all.
I probably wouldn't play the jund, esper, or naya ones.
As a somewhat out-there pick I'd also consider Pentad Prism. It allows for 5 mana on turn 3, which is pretty good. Of course, it's more like a ritual in that respect, similar in some ways to Grim Monolith. And it's only marginally worse than Sphere of the Suns in terms of total mana generation.
I think the trick is to get a critical mass of cards like Eureka, Show & Tell, Sneak Attack, Tinker, and Oath of Druids cards--in addition to tutors and the usual mana fixing--for this version of the "cheat-fatties" deck to work.
1. If you're trying to minimize redundancy where possible in your cube, it's hard to argue for him over Knight of the Reliquary. "Your" graveyard isn't typically all that different from "all" graveyards.
2. If you wanted to run more cards like this (and Countryside Crusher and aforementioned Knight), you might also look at including the Mirage fetches (Bad River, et. al.)
Whenever somebody drops a turn 1 Library, both players immediately know that player will win--but it will take forever, and it will be irritating for both players. That's a pretty good reason to not run it. Unless dealt with more or less immediately, or raced with a very fast deck, the card is basically unbeatable.
Last draft I saw this in, my teammate (on the draw) Mana Tithed a turn 3 Inferno Titan, then on his next turn, during his attack, Dark Ritualed to get 5 mana--just enough to Ninjitsu Ink-Eyes.
Also, Balefire Liege, which also happens to be decent in token decks (which for my cube are mostly Wr). I've included it, and it's been a phenomenal win-from-nowhere from time to time. It can threaten huge amounts of unblockable damage following an untap.
In addition to the above, I find that it is a very strong card in Planeswalker control decks and in heavy-artifact decks (since the Abyss can't kill artifact creatures).
It also increases the value of Sphinx of Jwar Isle (a card i'm not very fond of, because it's boring), because shroud prevents targeting by the effect. Morphling too, I suppose.
As for unmentioned cards: Runechanter's Pike can be a very powerful effect for very little mana (it's also a nice way to get some variety in your equipment).
Chandra's Spitfire, as mentioned above, is often criminally underrated. In many ways it's an improvement over Pyromancer's Swath (more vulnerable, but can be precast and gives an additional 3 damage instead of 2). Have it out with Gelectrode or Guttersnipe and every Ponder means 4 or 5 damage (in addition to the 5 already threatened). One of my best plays in cube involved no plays turn 1 or 2, a Chandra's Spitfire on turn 3, and then a turn 4 kill with Grapeshot pumping Spitfire immensely.
I don't know about Nivmagus Elemental. I have him in, but he hasn't seen any play yet. I think only storm and replicate are really going to make him worthwhile, but he does have a strong upside.
EDIT:
Also, Flame Jab and Shrine of Burning Rage are fantastic. Maybe Shrine of Piercing Vision could be good as well?
A bit about other colors.
I really wanted another color to help this deck out. I've been experimenting with green for Quirion Dryad, Search for Tommorrow, Rampant Growth, Nimble Mongoose, and Werebear. I want there to be more, but I haven't really found it (Call of the Herd / Beast Attack / other token makers?).
Black is also a candidate, for Yawg Will, Toshiro Umezawa, and Nightscape Familiar.
Intimidator Initiate is not good enough.
The way I've been building this in my cube is for it to blend with red aggro/burn (Kiln Fiend, Shrine of Burning Rage, Chandra's Spitfire, Guttersnipe, burn spells), Storm (Rituals, Card Draw, Ramp, Grapeshot), and other useful tools for tempo and control generally (cantrips, cheap spells). Since most of the cards in the deck legitimately belong in other decks, there is relatively little dedicated support that needs to be run. Delver, Nivmagus Elemental (if it lasts), and Runechanter's Pike are probably the most dedicated--everything else works well in other decks.
Generalized Winston
An n-player draft format.
The various players sit in a circle. Between each two players around the periphery of the circle, there is a pile of 45 cards and three one-card piles. Each player does the Winston process in the set to his left (look at one pile, choose yes/no, if yes take it; if no put a card atop the pile and o the same with the second pile, then the third; if still no then take a card from the top of the deck). Once each player has finished, each player does the process in the set to his right. So you're Winston drafting against 2 players, one on your left and one on your right. I particularly like this for 4-man team drafts.
Versatile, fun card.
I like the genjus (Genju of the Spires et. al)--they can be answered with Nature's Claim and Erase (which
should maybe be in as an answer to Rancor anyways).
This format seems like it will be dominated by the one-drop equipment--Trusty Machete et. al. You might want to replace Crush with Shattering Spree or Smelt, or even Vandalblast. 11 seems like a lot of equipment for 180 cards, anyways. But I'd definitely want a Kor Duelist.
I think I'd suggest the following cards as well.
Kuldotha Rebirth
Flame Jab
Raven's Crime
Devastating Summons.
Wax // Wane
Ezuri's Archers
Bandage
Curiosity
Hedron Crab (or other things to make Jace's Phantasm work--like perhaps Dream Twist?
Wingcrafter
Cards I'm not a fan of:
Mothdust Changeling
Spindrift Drake -- So redundant with Faerie Imposter and Drifter il-Dal
Mystic Penitent
Fastbond
I probably wouldn't play the jund, esper, or naya ones.
1. If you're trying to minimize redundancy where possible in your cube, it's hard to argue for him over Knight of the Reliquary. "Your" graveyard isn't typically all that different from "all" graveyards.
2. If you wanted to run more cards like this (and Countryside Crusher and aforementioned Knight), you might also look at including the Mirage fetches (Bad River, et. al.)
It also increases the value of Sphinx of Jwar Isle (a card i'm not very fond of, because it's boring), because shroud prevents targeting by the effect. Morphling too, I suppose.
But yes, it can lead to oppressive games.
The truth is that the majority of red and blue cheap spells (especially cantrips) go very well in the archetype. It's one reason I run Ponder, Brainstorm, Preordain, Serum Visions, Thought Scour, and Sleight of Hand as one-mana blue cantrips in my ~600. Of course, they're also good in most other blue decks. Of course, Snapcaster Mage is fantastic in the archetype (as he always is in UR), as are Augur of Bolas and Kiln Fiend and Guttersnipe and Talrand.
As for unmentioned cards:
Runechanter's Pike can be a very powerful effect for very little mana (it's also a nice way to get some variety in your equipment).
As mentioned above, Gelectrode is a house.
Chandra's Spitfire, as mentioned above, is often criminally underrated. In many ways it's an improvement over Pyromancer's Swath (more vulnerable, but can be precast and gives an additional 3 damage instead of 2). Have it out with Gelectrode or Guttersnipe and every Ponder means 4 or 5 damage (in addition to the 5 already threatened). One of my best plays in cube involved no plays turn 1 or 2, a Chandra's Spitfire on turn 3, and then a turn 4 kill with Grapeshot pumping Spitfire immensely.
I don't know about Nivmagus Elemental. I have him in, but he hasn't seen any play yet. I think only storm and replicate are really going to make him worthwhile, but he does have a strong upside.
EDIT:
Also, Flame Jab and Shrine of Burning Rage are fantastic. Maybe Shrine of Piercing Vision could be good as well?
A bit about other colors.
I really wanted another color to help this deck out. I've been experimenting with green for Quirion Dryad, Search for Tommorrow, Rampant Growth, Nimble Mongoose, and Werebear. I want there to be more, but I haven't really found it (Call of the Herd / Beast Attack / other token makers?).
Black is also a candidate, for Yawg Will, Toshiro Umezawa, and Nightscape Familiar.
Intimidator Initiate is not good enough.
The way I've been building this in my cube is for it to blend with red aggro/burn (Kiln Fiend, Shrine of Burning Rage, Chandra's Spitfire, Guttersnipe, burn spells), Storm (Rituals, Card Draw, Ramp, Grapeshot), and other useful tools for tempo and control generally (cantrips, cheap spells). Since most of the cards in the deck legitimately belong in other decks, there is relatively little dedicated support that needs to be run. Delver, Nivmagus Elemental (if it lasts), and Runechanter's Pike are probably the most dedicated--everything else works well in other decks.
A 2-player variant that combines elements of Winston and Winchester. Described here: https://www.wizards.com/magic/magazine/article.aspx?x=mtg/daily/ld/143
Generalized Winston
An n-player draft format.
The various players sit in a circle. Between each two players around the periphery of the circle, there is a pile of 45 cards and three one-card piles. Each player does the Winston process in the set to his left (look at one pile, choose yes/no, if yes take it; if no put a card atop the pile and o the same with the second pile, then the third; if still no then take a card from the top of the deck). Once each player has finished, each player does the process in the set to his right. So you're Winston drafting against 2 players, one on your left and one on your right. I particularly like this for 4-man team drafts.