Mortuary + Phyrexian Dreadnought + Susurian Voidborn + Gwenom, Remorseless

Mortuary

Phyrexian Dreadnought

Susurian Voidborn

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 Susurian Voidborn trigger.
4. Resolve the Mortuary trigger, putting Phyrexian Dreadnought from your graveyard onto the top of your library.
5. Resolve the Susurian Voidborn trigger, causing you to gain 1 life and target opponent to lose 1 life.
6. Repeat.