Never saw that Legendary before, looks sweet. +1 UPVOTE. Especially because of your Commander!

Heh yeah, Atraxa is a big threat when she comes out. Tons of fun. Just make sure you can keep her protected!

Personally I'd recommend cutting Night Soil for Necrogenesis. I don't know if you have it for any particular reason but necrogenesis is a lot more flexible, both in mana cost and in targeting options.

I dont see how Night Soil isn't better? Better chance of me having 2 greens than a black and green, and 1 mana for 2 creatures exiled instead of 2 mana for 1 creature?

If you mill someone's entire deck with villainous wealth then they lose their next turn and all the permanents you just got are removed from the game.

Which could have still triggered effects like Cathars' Crusade, Deathreap Ritual, Death's Presence, etc. Or win the game anyway. Or you can mill all but the last few cards, etc. A number of ways to play it, which is what i like. But i edited description to reflect that issue. :) thanks!

The 6 signets (Simic Signet) should be in here imho, as they ramp little,but color fix a lot. There are 10 but only 6 usable as 4 have red.

I agree the signets would be a good addition, but I think you need a few more lands as well. I've been building an Atraxa deck as well and the manabase is fiddly. I'm not sure what your budget is but a reasonable option is adding in check lands (Glacial Fortress, Sunpetal Grove, etc) and pain lands (Yavimaya Coast, Llanowar Wastes, etc). The expensive option is adding filters (Wooded Bastion, Flooded Grove etc) and shocks (Hallowed Fountain, Godless Shrine etc). If you can swing it, the checks and shocks pair very well together. You could probably throw in some extra sources of ramp such as Cultivate Explore Kodama's Reach Commander's Sphere and Fellwar Stone

Think I'll add in Tamiyo, Field Researcher and Tamiyo, the Moon Sage - the play from graveyard will help keep my Commander cost low, and the Cast from Hand At No Cost will help me cheat out cards... But combined?

What do u mean exactly by "both combined"??

Rewriting for clarity.

Get the emblem for one, then the other. I mean you can't have both cards out at the same time, but the emblem for one could be gotten in one turn if you can also cast Deepglow Skate, but you can proliferate quick to get it if you can't.

Then get the second and have fun.

Ashnod's Altar? Infinite mana because you sac a creature, it goes to your graveyard, it goes back to your hand where you can cast it for free again -- infinite colorless mana. Same with Krark-Clan Ironworks but using artifacts. Or Altar of Dementia and infinitely mill all their libraries for the win.

In most decks it'd take forever to do it, but not in a proliferate deck. So 3 card win condition over a couple turns if need be, and I have tutors and return from graveyard, so it's a decent chance to win.

Sounds lands to consider: Ash Barrens, Terramorphic Expanse, Esper Panorama, Opal Palace. The Lair's can help with fixing too Treva's Ruins & Dromar's Cavern. Or add more storage type lands like Dreadship Reef to take advantage of Proliferate.

I might add a few more rocks too, like Everflowing Chalice, Commander's Sphere, and Gemstone Array.

Gyre Sage is cool here too.

This seems like a solid deck so +1 for that. Have you considered Eldritch Evolution? You could use almost any creature you have on the battlefield with your CMC's to go and get any creature out of your deck that fits the situation and could potentially win you the game.

Eldritch Evolution might be useful but I don't know if it would be that effective. I have 2 tutors and 2 cast from graveyard already, and a planeswalker that can permanently let me cast cards from hand without paying the cost (once my other tamiyo arrives). But it's a maybe, and definitely a card I want to keep in mind for other decks, so thanks :D

I propose that you should replace Villainous Wealth with Exsanguinate for your infinite colorless mana wincon. Why? Because it doesn't target just one opponent, it targets all opponents on one fell swoop, as opposed to having to target one player and hope that their milled cards contains a wincon. Additionally, it's cheaper CMC wise, you don't have infinite mana of any color, just colorless...so just having to spend seems a bit more feasible.

Well I prefer Necrogenesis over Night Soil because of how it seems it's supposed to be used. The intent of the cards from what I can tell is that they're good for making saporlings and the graveyard hate is a solid upside. Since you're running Cathars' Crusade, Ashnod's Altar, etc they seem to fit well for that goal. Even though night soil does have a cheaper activated ability the fact that you have to target two creatures limits how you can use it and halves how many times it can be done. If you're running it for graveyard hate there a lot of other options that are more effective, I'd go for Relic of Progenitus, Anafenza, the Foremost, or Rest in Peace.

Hmm. Relic of Progenitus is a pretty good idea, and Anafenza, the Foremost will go on my Maybe board - thanks

Not 100% on what you should pull, but you should consider adding Drana, Liberator of Malakir. She is amazing in an Atraxa deck.

Ooh,good recommendation!