Mortuary + Bolas's Citadel + Bloodflow Connoisseur + Shield Sphere

Mortuary

Bolas's Citadel

Bloodflow Connoisseur

Shield Sphere

How it works

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

This clever loop turns zero-mana artifacts into an endless engine of sacrifice and rebirth by letting Bolas's Citadel play right off the top of your library while bypassing mana costs with life. When you feed Shield Sphere to Bloodflow Connoisseur, Mortuary immediately catches the dying zero-cost wall and places it right back onto the top of your library. Because Bolas's Citadel allows you to replay that top card for zero life, you can instantly recast Shield Sphere and repeat the entire sequence to endlessly pump Bloodflow Connoisseur and rack up unlimited triggers.