Mortuary + Sarcatog + Bolas's Citadel + Ornithopter

Mortuary

Sarcatog

Bolas's Citadel

Ornithopter

How it works

1. Activate Sarcatog by sacrificing Ornithopter
2. When Ornithopter dies, Mortuary triggers, putting Ornithopter from your graveyard onto the top of your library.
3. Resolve the Sarcatog ability.
4. Cast Ornithopter from the top of your library by paying 0 life.
5. Repeat.

This clever loop lets you turn the zero-mana cost of Ornithopter into an infinite engine by leveraging Mortuary's triggered ability to recycle the tiny artifact creature straight back to the top of your library every time it hits the graveyard. Sarcatog acts as the sacrifice outlet that enables this cycle, though its ability to eat cards from your graveyard or pump itself is largely secondary to its role in sending the thopter away. Meanwhile, Bolas's Citadel provides the crucial top-deck infrastructure, allowing you to continually recast Ornithopter directly from your library for zero life instead of its usual mana cost, ultimately generating infinite death triggers, storm count, and an infinitely massive Sarcatog.