Bringer of the Last Gift

The trigger reads like a graveyard reset button, but the "if you cast it" clause is the whole engine: reanimation cheats built to sidestep the mana cost also disable the payoff, so this Vampire Demon rewards the one thing eight-mana bombs usually try to avoid, which is actually hardcasting it. The sequence is a two-part wrath: first every player sacrifices all their other creatures, then every player returns every creature card that was already in a graveyard, meaning the corpses you fed the yard beforehand come back while fresh sacrifices stay dead. That ordering is the point. A board you built to die on the way down becomes a board you rebuild on the way back up, and because the return is symmetric, the edge goes to whoever stocked their graveyard deepest and cheapest before this ever hit the stack. It punishes go-wide opponents (their army gets swept) while padding your own reanimation shell, folding a board wipe and a mass reanimation spell into a single body that also happens to be a 6/6 flier. The design lineage runs through mass-reanimation effects that trade their own conditions for scale; this one puts the whole package on a creature and gates the best half behind casting it, so the demon that should be a graveyard payoff is instead the reason to build the graveyard in the first place.