Mortuary + Cauldron Familiar + Bolas's Citadel + Bloodflow Connoisseur

Mortuary

Cauldron Familiar

Bolas's Citadel

Bloodflow Connoisseur

How it works

1. Cast Cauldron Familiar either from your hand or from the top of your library by paying or 1 life respectively.
2. When Cauldron Familiar enters, it triggers, causing each opponent to lose 1 life and you to gain 1 life.
3. Activate Bloodflow Connoisseur by sacrificing Cauldron Familiar.
4. When Cauldron Familiar dies, Mortuary triggers, putting Cauldron Familiar from your graveyard onto the top of your library.
5. Resolve the Bloodflow Connoisseur ability.
6. Repeat.

This loop transforms the top of your library into an endless engine of life drain and sacrifice by turning Bloodflow Connoisseur and Mortuary into a recycling machine for Cauldron Familiar. Whenever the Cat enters the battlefield, it triggers its life drain while Bolas's Citadel lets you recast it directly from the top of your library by paying life instead of its mana cost. Bloodflow Connoisseur provides the convenient sacrifice outlet needed to send Cauldron Familiar back to the graveyard, where Mortuary immediately intercepts it to place it right back on top of your library.