Mortuary + Altar of Dementia + Bolas's Citadel + Serrated Scorpion

Mortuary

Altar of Dementia

Bolas's Citadel

Serrated Scorpion

How it works

1. Activate Altar of Dementia by sacrificing Serrated Scorpion.
2. When Serrated Scorpion dies, it and Mortuary triggers.
3. Resolve the Mortuary trigger, putting Serrated Scorpion from your graveyard onto the top of your library.
4. Resolve the Serrated Scorpion trigger, causing you to gain 2 life and dealing 2 damage to each opponent.
5. Resolve the Altar of Dementia ability.
6. Cast Serrated Scorpion from the top of your library by paying 1 life due to Bolas's Citadel.
7. Repeat.

This clever loop sets up an endless cycle of sacrifice and rebirth by letting Altar of Dementia feed the grim recycling machinery of Mortuary. Every time Serrated Scorpion is sent to the graveyard, Mortuary instantly places it back onto the top of your library where Bolas's Citadel allows you to recast it for a mere 1 life. Meanwhile, Serrated Scorpion's own death trigger uses your life-gain buffer to effortlessly offset the Citadel's mana value costs, letting you mill opponents out and drain their life totals to zero without ever spending a single drop of actual mana.