Leonardo, Sewer Samurai + Solemnity + Ornithopter + Phantom Train

Leonardo, Sewer Samurai

Solemnity

Ornithopter

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Ornithopter.
2. Cast Ornithopter from your graveyard by paying 0. It will not enter with a finality counter on it due to Solemnity.
3. Repeat.

This clever loop leverages Leonardo, Sewer Samurai's ability to let you recast tiny creatures from your graveyard on your turn, specifically targeting the free, zero-mana Ornithopter. Meanwhile, Phantom Train acts as the sacrifice outlet that pumps itself with +1/+1 counters while eating the Ornithopter over and over. The real magic tying the engine together is Solemnity, whose passive enchantment effect completely bypasses Leonardo, Sewer Samurai's finality counters and ensures the Ornithopter never stays exiled.