Rotlung Reanimator + Arcane Adaptation + Phantom Train

Rotlung Reanimator

Arcane Adaptation

Phantom Train

How it works

1. Activate Phantom Train by sacrificing any other creature.
2. When the creature dies as a Cleric due to Arcane Adaptation, Rotlung Reanimator triggers, creating a 2/2 Zombie creature token.
3. Resolve the Phantom Train ability.
4. Repeat.

By casting Arcane Adaptation and naming "Cleric," you fundamentally rewrite the rules of your battlefield: every creature spell and permanent you own instantly gains the Cleric creature type alongside its original types. This transforms Phantom Train's sacrifice outlet into a ruthless engine, since any creature you feed to it is recognized as a dying Cleric. That death immediately triggers Rotlung Reanimator to spawn a fresh 2/2 Zombie token, which can be sacrificed right back to Phantom Train to pile up infinite +1/+1 counters while triggering endless enters-the-battlefield, leaves-the-battlefield, and death events.