Mortuary + Megatog + Bolas's Citadel + Shield Sphere

Mortuary

Megatog

Bolas's Citadel

Shield Sphere

How it works

1. Activate Megatog 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 Megatog ability.
4. Cast Shield Sphere from the top of your library by paying 0 life.
5. Repeat.

This loop transforms the free artifact-sacrifice outlet Megatog into an infinite pump engine by feeding it Shield Sphere over and over again. The crucial enabler here is Mortuary, which acts as a bridge between the graveyard and your library, intercepting Shield Sphere the moment it dies to quietly place it right back on top. Meanwhile, Bolas's Citadel allows you to play that very same Shield Sphere directly from your library for zero life, completely bypassing traditional mana costs and card draw.