(6/16/2023) Denethor, Ruling Steward's first ability will trigger only once during your end step, no matter how many creatures died under your control this turn
Kroxa provides low opportunity cost inevitability to these decks, allowing them to win grindy games, which is key to giving Rakdos decks that bit of extra texture that sets them apart
Brachydios and Nargacuga seem like the standouts here

Quandrix students, help me count to five: Primo, the Unbounded, which I will absolutely be building, introducing the first-ever base-power-0 matters commander that builds big Fractal tokens when creatures with 0 base power deal combat damage Yavimaya Bloomsage, the only creature in the prepare cycle to feature a flat-out banned card in Channel, made ready by putting a +1/+1 counter on a creature that subsequently has power 7 or greater Owlin Spiralmancer, a powerful creature that copies the first X-cost spell you cast every turn (including on your opponents' turns) Nexus Mentality, a member of the highly exclusive club of cards that can move counters between nonland permanents (sadly, this doesn't let you rip counters away from Dark Depths) Turbulent Wilderness, the final land (for now) in the Turbulent cycle When it comes to blue-green, it can sometimes be difficult to build a deck with a cohesive theme that doesn't lean too hard on broad themes like +1/+1 counters or Lands Matter

Well theres currently a damaged one sitting on TCGplayer for $21 shipped, sold by The End Games