This deck is based on a nine-year-old Standard deck by Frank Karsten. I liked it a lot -- not only because I really like Chromanticore, but because it could be effectively rendered in Budget Modern. However, there were various compromises made due to the fact that, well, this was the Standard of nine years ago; the number of cards designed since then has all but doubled. Additionally, I wasn't nearly as good at Scryfall-fu back then; there have been some fluctuations in card price; and I started wondering if I could make it Pioneer-legal. So I gave it another whack.
As before, this is fundamentally a Graveyard Shenanigans deck. The basic idea is to use Satyr Wayfinder and/or Commune with the Gods on Turn 2, enabling a Soulflayer as early as Turn 3. Obviously, it's luck as to what keywords it lands with, but if you've got some combination of Leyline Prowler, Swiftblade Vindicator and Chromanticore, you're already on your way.
All of the rest is just support. Anything that's worth casting is worth chump-blocking with (or sacrificing to Bone Splinters and Deadly Brew), because it'll come back under a Soulflayer. The sole exceptions are the Wayfinder, which is the only creature in the deck with no keywords; and the Prowler and Deathbloom Gardener, which you'll probably want to keep a couple on the board to support your secondary wincon of Bestowing the Chromanticore on something. Hazoret the Fervent, Splinters and Brew give us limited ability to get specific cards into the graveyard; the former also serves as a tertiary wincon, in case we needed one. And Deadly Brew gives us an answer if we accidentally mill a Soulflayer, something which Mr. Karsten's original did not include, presumably because no card existed in the Standard of the time that fit the purpose.
I tend to build goldfish decks, but if you're looking for interaction, you can make do with basically one less of any spell in the deck. (Like I said, I tend to build goldfish decks.) Meanwhile, the Maybeboard has my suggestions for what to add in. Beyond that, the most obvious upgrade path is to replace the Gardeners and the Gladecover Scouts with a set of Sylvan Caryatids: four of them are unquestionably better than all six copies of what it's replacing, but it -- or, rather, the fact that it went from $0.70 to $7.00 and then stayed there for years -- is also the main reason I created the revision you're looking at now. Finally, while Leyline Prowler / Deathbloom Gardener / Sylvan Caryatid will be able to support you to limited extents, you might want to look into five-color lands, particularly if you want to add in the counterspells Frank Karsten used to stall in the original version. (Mana Confluence is the only Pioneer-legal one that doesn't come into play tapped, cost , tap additional creatures or have provisos on what you can use the mana for; naturally, it's more expensive than this whole deck. Guess we're back to Rupture Spire...)
For a much less budget-conscious implementation of this idea, see here.
