Mortuary + Skirk Prospector + Bolas's Citadel + Vengeful Bloodwitch

Mortuary

Skirk Prospector

Bolas's Citadel

Vengeful Bloodwitch

How it works

1. Activate Skirk Prospector by sacrificing it.
2. When Skirk Prospector dies, Mortuary and Vengeful Bloodwitch trigger.
3. Resolve the Mortuary trigger, putting Skirk Prospector from your graveyard onto the top of your library.
4. Resolve the Vengeful Bloodwitch trigger, causing you to gain 1 life and target opponent to lose 1 life.
5. Cast Skirk Prospector from the top of your library by paying 1 life.
6. Repeat.

This clever loop turns Skirk Prospector into a self-sustaining engine by leveraging Bolas's Citadel to cast creatures directly from the top of your library using life instead of mana. Whenever the Goblin is sacrificed for red mana, Mortuary catches it on its way to the graveyard and immediately places it right back onto the top of your library, perfectly positioned for the Citadel to play it again. Meanwhile, Vengeful Bloodwitch watches the carnage unfold, draining your opponents' life totals with every single cycle.