Mikaeus, the Unhallowed + Blood Pet + Hex Parasite + Pawn of Ulamog

Mikaeus, the Unhallowed

Blood Pet

Hex Parasite

Pawn of Ulamog

How it works

1. Activate Blood Pet by sacrificing it, adding .
2. When Blood Pet dies, its undying ability and Pawn of Ulamog trigger.
3. Resolve the Blood Pet trigger, returning it to the battlefield from your graveyard with a +1/+1 counter on it.
4. Resolve the Pawn of Ulamog trigger, creating a 0/1 Eldrazi Spawn creature token.
5. Activate the Eldrazi Spawn by sacrificing it, adding C.
6. Activate Hex Parasite by paying 1B/P and removing the +1/+1 counter from Blood Pet, giving Hex Parasite +1/+0 until end of turn.
7. Repeat.

This ingenious loop relies on Mikaeus, the Unhallowed to grant undying to Blood Pet, letting the tiny creature continuously resurrect itself with a +1/+1 counter whenever it is sacrificed for mana. However, because undying can only trigger if the creature had no counters on it, Hex Parasite steps in as the crucial pressure valve, using its ability to strip away that +1/+1 counter by paying life and mana. Meanwhile, Pawn of Ulamog watches the endless cycle of deaths and generates Eldrazi Spawn tokens to help fuel the necessary mana costs, ultimately creating an engine that churns out infinite sacrifices, triggers, and a massively pumped Hex Parasite.