Ashiok's Reaper + Mortuary + Phyrexian Altar + Hateful Eidolon

Ashiok's Reaper

Mortuary

Phyrexian Altar

Hateful Eidolon

How it works

1. Activate Phyrexian Altar by sacrificing Hateful Eidolon, adding .
2. When Hateful Eidolon dies, Mortuary and Ashiok's Reaper trigger.
3. Resolve the Mortuary trigger, putting Hateful Eidolon on top of your library from your graveyard.
4. Resolve the Ashiok's Render trigger, causing you to draw Hateful Eidolon from your library.
5. Cast Hateful Eidolon by paying .
6. Repeat.

This ingenious loop relies on Phyrexian Altar to feed Hateful Eidolon to its sacrifice engine while simultaneously generating the black mana needed to recast it. As the Eidolon hits the graveyard, Mortuary intercepts it to place it right back on top of your library, seamlessly bypassing the need to redraw it traditionally. Instead, Ashiok's Reaper triggers off the enchantment card leaving the battlefield to instantly draw Hateful Eidolon back into your hand, ready to be cast all over again.