Mortuary + Altar of Dementia + Shield Sphere + Gwenom, Remorseless

Mortuary

Altar of Dementia

Shield Sphere

Gwenom, Remorseless

How it works

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

This elegant loop turns the humble, free-to-cast Shield Sphere into an infinite milling engine. By sacrificing the Sphere to Altar of Dementia, you trigger Mortuary, which immediately rescues the artifact creature from your graveyard and places it right back on top of your library. From there, Gwenom, Remorseless steps in as the enabler, allowing you to cast spells directly off the top of your library while bypassing traditional mana costs in exchange for paying life—which Shield Sphere graciously does for a mere zero life.