Mortuary + Phyrexian Dreadnought + Vengeful Bloodwitch + Gwenom, Remorseless

Mortuary

Phyrexian Dreadnought

Vengeful Bloodwitch

Gwenom, Remorseless

How it works

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

This elegant loop relies on Gwenom, Remorseless to turn the top of your library into an active hand, allowing you to cast Phyrexian Dreadnought repeatedly by paying its life cost rather than its mana value. The moment the Dreadnought hits the battlefield, its massive power demands a sacrifice, instantly sending it to the graveyard and triggering Mortuary to seamlessly recycle it right back to the top of your library. Meanwhile, Vengeful Bloodwitch watches the carnage from the battlefield, converting every single death into an unstoppable drain of life until your opponents are completely overwhelmed.