Cauldron of Souls + Dross Scorpion + Shilgengar, Sire of Famine + Biotransference

Cauldron of Souls

Dross Scorpion

Shilgengar, Sire of Famine

Biotransference

How it works

1. Activate Cauldron of Souls by tapping it, giving the creature with bloodthirst persist until end of turn.
2. Activate Shilgengar by sacrificing the creature with bloodthirst.
3. When the creature dies, its persist ability and Dross Scorpion trigger.
4. Resolve the persist trigger, returning the creature from your graveyard to the battlefield, which enters the battlefield with at least one +1/+1 counter on it due to its bloodthirst ability.
5. Resolve the Dross Scorpion trigger, untapping Cauldron of Souls.
6. Resolve the Shilgengar ability
7. Repeat.

This ingenious loop turns Shilgengar, Sire of Famine into an engine of endless sacrifice by utilizing Biotransference to transform your entire board into artifacts. Thanks to that continuous enchantment, sacrificing a creature to Shilgengar triggers Dross Scorpion, which untaps Cauldron of Souls so it can grant persist to your creatures over and over. When your creature dies, the persist trigger brings it right back, and the +1/+1 counters from its bloodthirst ability immediately cancel out the -1/-1 counter it would otherwise accumulate.