Remembrance + Deathrender + Arashin Sovereign + Phyrexian Altar

Remembrance

Deathrender

Arashin Sovereign

Phyrexian Altar

How it works

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