Mortuary + Krark-Clan Ironworks + Bolas's Citadel + Shield Sphere

Mortuary

Krark-Clan Ironworks

Bolas's Citadel

Shield Sphere

How it works

1. Activate Krark-Clan Ironworks by sacrificing Shield Sphere
2. When Shield Sphere dies, Mortuary triggers, putting Shield Sphere from your graveyard onto the top of your library.
3. Cast Shield Sphere from the top of your library by paying 0 life.
4. Repeat.

This intricate loop turns the humble Shield Sphere into an absolute powerhouse by leveraging the artifact-sacrificing prowess of Krark-Clan Ironworks to generate endless colorless mana and death triggers. Because Bolas's Citadel allows you to play spells directly from the top of your library by paying life instead of mana, you can cast the zero-mana Shield Sphere repeatedly for zero life. Meanwhile, Mortuary watches over your graveyard, effortlessly placing the fallen Shield Sphere right back onto the top of your library each time it dies, ensuring your fuel never runs dry.