Guan Yu, Sainted Warrior + Remembrance + Deathrender + Phyrexian Altar

Guan Yu, Sainted Warrior

Remembrance

Deathrender

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Guan Yu, adding one mana of any color.
2. When Guan Yu dies, it, Deathrender and Remembrance trigger.
3. Resolve the Guan Yu trigger, causing you to shuffle it into your library from your graveyard.
4. Resolve the Remembrance trigger, causing you to search your library for Guan Yu and put it into your hand.
5. Resolve the Deathrender trigger, putting Guan Yu from your hand onto the battlefield, and attaching Deathrender to it.
6. Repeat.

This ingenious loop relies on a clever intersection of triggers to constantly recycle a single legendary warrior. When you feed Guan Yu, Sainted Warrior to Phyrexian Altar, his own death trigger lets you shuffle him right back into your library, but Remembrance intercepts that journey by tutoring him directly to your hand instead. Meanwhile, Deathrender ensures that whenever the equipped Guan Yu dies, he immediately drops back onto the battlefield equipped and ready to be sacrificed to the Altar all over again.