Nethroi, Apex of Death + Phyrexian Altar + Mitotic Slime + Quickling

Nethroi, Apex of Death

Phyrexian Altar

Mitotic Slime

Quickling

How it works

1. Cast Nethroi either from your hand or from the command zone for its mutate cost by paying 4G/W, putting it under a non-Human creature you control.
2. Nethroi triggers, returning Quickling and Mitotic Slime from your graveyard to the battlefield.
3. When Quickling enters, it triggers, returning Nethroi from the battlefield to your hand.
4. Activate Phyrexian Altar twice by sacrificing Quickling and Mitotic Slime, adding .
5. When Mitotic Slime dies, it triggers, creating two 2/2 Ooze creature tokens.
6. Activate Phyrexian Altar twice by sacrificing the Oozes, adding 1G/W.
7. When the Oozes die, they trigger, creating four 1/1 Ooze creature tokens.
8. Activate Phyrexian Altar three times by sacrificing three Oozes, adding 3.
9. Repeat.

This intricate engine spins up by leveraging Nethroi, Apex of Death's explosive mutate trigger to pull Mitotic Slime and Quickling straight from your graveyard to the battlefield. As Quickling enters, its self-sacrifice clause forces you to bounce Nethroi right back to your hand, locking in a repeating loop of cast, mutate, and bounce. Meanwhile, Phyrexian Altar provides the crucial mana generation needed to recast Nethroi by turning the resulting cascade of Ooze tokens—created by Mitotic Slime's successive dying triggers—into a steady stream of colored mana.