Bloodthirster

The extra-combat-step reward has a long design history (Aggravated Assault, Waves of Aggression, Relentless Assault), but those effects always bolted onto some other attacker. Here the loop is self-contained: the body earns its own follow-up phase by connecting, untapping itself and generating the next combat step in one trigger, so the demon is both engine and payload. The constraint that keeps this from being a single-creature turn-loop is precise and easy to miss: it cannot attack a player it has already attacked this turn. Against a lone opponent, that ceiling bites immediately. The extra combat phase still happens, but the demon itself can't attack that same player again, so its untap does nothing for it and the chain generates a phase with no legal target for the generator. The card is built for multiplayer tables, where each new combat step opens a fresh player to point it at, and the additional phases keep coming as long as there are opponents it has not yet attacked. That reframes the reward entirely: a 6/6 flyer with trample facing three opponents becomes a repeatable extra-combat generator, but only as wide as the pod is. It is a design that scales with the number of players rather than the strength of one, which is why the untap-and-attack-again payoff lands differently here than on the older enchantment versions that never cared how many people you were fighting.