Mikaeus, the Unhallowed

Undying is normally a one-shot resurrection: a creature dies, returns enlarged, and the counter it comes back with is the off-switch the next time it dies. What this card contributes to a combo table is not a rewrite of that rule but the act of granting undying to every other non-Human you control. The loop runs because of what you pair the grant with, not because the brake has been removed. A creature returning enlarged still stays dead the second time it dies; the engine needs a body that can clear its own counter, which is why the textbook line uses Triskelion (remove a counter to ping, die, return fresh, repeat until the opponent hits zero) or pairs the undying grant with persist creatures, where the persist -1/-1 counter cancels the +1/+1 and leaves the creature primed to loop again. The Human-destroying clause and the color-locked evasion are functional, but they are not why this card built a combo identity around a 5/5 commander. The anthem half quietly excludes Humans from both the buff and the undying grant, a self-imposed tribal restriction that reads as flavor (an unhallowed cleric ruling the dead, not the living) while aiming the engine at the creatures that can actually abuse it. Among the cards that turn undying into infrastructure rather than insurance, this is the one that does it by handing the keyword out, then letting a counter-shuffling partner finish the job.