Mortuary + Phyrexian Altar + Tarpan + Gwenom, Remorseless

Mortuary

Phyrexian Altar

Tarpan

Gwenom, Remorseless

How it works

1. Activate Phyrexian Altar by sacrificing Tarpan.
2. When Tarpan dies, it and Mortuary triggers.
3. Resolve the Mortuary trigger, putting Tarpan from your graveyard onto the top of your library.
4. Resolve the Tarpan trigger, causing you to gain 1 life
5. Cast Tarpan from the top of your library by paying 1 life due to Gwenom.
6. Repeat.

This clever loop turns a humble centaur into a self-sustaining engine by letting Gwenom, Remorseless peer into your library and bypass mana costs with life payments instead. When you sacrifice Tarpan to Phyrexian Altar, you not only net a colored mana, but you also trigger its life-gain ability to instantly offset the life you spent to recast it. Meanwhile, Mortuary intercepts the dying creature to neatly restack it on top of your library, seamlessly resetting the entire sequence for endless repetition.