Su-Chi + Oathkeeper, Takeno's Daisho + Xenograft + Phyrexian Altar

Su-Chi

Oathkeeper, Takeno's Daisho

Xenograft

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Su-Chi, adding one mana of any color.
2. Su-Chi and Oathkeeper triggers.
3. Resolve the Su-Chi trigger, adding CCCC.
4. Resolve the Oathkeeper trigger, returning Su-Chi to the battlefield.
5. Equip Oathkeeper to Su-Chi by paying 2.
6. Repeat.

This clever loop relies on Xenograft to rewrite the creature types of your entire board, making Su-Chi a Samurai so that it qualifies for Oathkeeper, Takeno's Daisho's resurrection ability. By sacrificing Su-Chi to Phyrexian Altar, you generate a mana of any color while triggering both Su-Chi's death mana and the Equipment's return trigger. Resolving these puts Su-Chi right back onto the battlefield, where you simply reattach Oathkeeper, Takeno's Daisho for two mana—leaving you with a net profit of colored and colorless mana to fuel whatever devastating finisher you desire.