Demonic Rising

The condition does the entire heavy lifting here: a recurring engine that only fires when you control exactly one creature, a deeply unusual gate for a token-maker to wear. Most repeatable creature-generators want a wide board to compound on; this one wants a single occupant, and that inversion is the design's whole reason for being. You need at least one creature in play for it to do anything (an empty board fires nothing), but the moment it succeeds, the new 5/5 Demon pushes you to two creatures and shuts the enchantment off until the board narrows back to one. So it self-paces: keep a lone threat alive and it drip-feeds fliers one at a time, replacing each as the previous one trades or dies. It rewards a deliberately lean build, which runs against the grain of how black usually floods the board. The end-step timing shapes how each token enters rather than locking it down. The Demon arrives after combat and after the sorcery-speed window has closed, so it never ambushes as a blocker and cannot attack the turn it appears, but priority still passes around the end step once the trigger resolves: you can crew a vehicle with it or feed it to an instant-speed sacrifice outlet before you pass the turn. Waiting until you have already committed also lets it sidestep the sweeper-on-your-own-turn problem. It is a control-leaning attrition piece wearing the costume of a beater, asking you to grind out one 5/5 per turn rather than overextend into the next board wipe.