Oathsworn Vampire + Phyrexian Altar + Totentanz, Swarm Piper

Oathsworn Vampire

Phyrexian Altar

Totentanz, Swarm Piper

How it works

1. Activate Phyrexian Altar by sacrificing Oathsworn Vampire, adding .
2. When Oathsworn Vampire dies, Totentanz triggers, creating a creature token.
3. Activate Phyrexian Altar by sacrificing the creature token, adding 1.
4. Cast Oathsworn Vampire from your graveyard by paying 1.
5. Repeat.

This crafty loop turns a simple lifecycle of sacrifice and resurrection into an infinite engine, powered entirely by Phyrexian Altar's mana generation. When you sacrifice Oathsworn Vampire to the Altar, its death prompts Totentanz, Swarm Piper to spawn a Rat token, which you immediately sacrifice back to the Altar for the remaining mana needed. Because the Vampire's death naturally grants you life—or relies on an external life gain source to satisfy its condition—you can recast Oathsworn Vampire directly from your graveyard, resetting the loop for endless death and sacrifice triggers.