Mairsil, the Pretender + Carnifex Demon + Cauldron of Souls + Blood Pet + Anger

Mairsil, the Pretender

Carnifex Demon

Cauldron of Souls

Blood Pet

Anger

How it works

1. Activate Mairsil using Cauldron of Souls' ability by tapping it, giving itself persist until end of turn.
2. Activate Mairsil using Blood Pet's ability by sacrificing it, adding .
3. When Mairsil dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
4. Activate Mairsil using Carnifex Demon's ability by paying and removing a -1/-1 counter from it, putting a -1/-1 counter on each other creature.
5. Repeat.

This clever loop turns Mairsil, the Pretender into a self-sustaining engine by cage-countering key components from your graveyard and hand. Mairsil adopts Cauldron of Souls' activated ability to grant itself persist, which allows it to return to the battlefield with a -1/-1 counter whenever it dies. To fuel this recursion, you sacrifice Mairsil using Blood Pet's ability for black mana, and once Mairsil returns via persist, you spend that mana to activate Carnifex Demon's ability—paying {B} and removing the -1/-1 counter that persist just placed on Mairsil. Meanwhile, Anger rests quietly in your graveyard, ensuring that Mairsil and your other creatures have haste as long as you control a Mountain so the loop can start right away.