Leonardo, Sewer Samurai + Solemnity + Atog + Ornithopter

Leonardo, Sewer Samurai

Solemnity

Atog

Ornithopter

How it works

1. Activate Atog 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 transforms a humble zero-mana flyer into an infinite sacrifice engine by turning Leonardo, Sewer Samurai's graveyard-casting restriction into a non-issue. Thanks to Solemnity's static ability preventing counters from being placed on permanents, Leonardo's finality counters never actually land on Ornithopter when you replay it from the graveyard. You can then feed that same Ornithopter directly into Atog's activated ability, instantly pumping it to astronomical proportions while generating an endless stream of artifact sacrifices, enters-the-battlefield triggers, and storm count.