Feldon of the Third Path + Thornbite Staff + Cathodion + Phyrexian Altar

Feldon of the Third Path

Thornbite Staff

Cathodion

Phyrexian Altar

How it works

1. Activate Feldon of the Third Path by paying 2 and tapping it, creating a token copy of Cathodion with haste.
2. Activate Phyrexian Altar by sacrificing the Cathodion token, adding .
3. When the Cathodion token dies, it and Feldon of the Third Path trigger.
4. Resolve the Feldon of the Third Path trigger, untapping it.
5. Resolve the Cathodion trigger, adding CCC.
6. Repeat.

This clever engine turns Feldon of the Third Path into a tireless artificer by looping a very specific metallic minion. With Cathodion in your graveyard, Feldon uses his ability to churn out hasty token copies. When you sacrifice that token to Phyrexian Altar for colored mana, Cathodion's own death trigger kicks in to reward you with three colorless mana—more than enough to fund Feldon's next activation and leave you with a growing surplus. While Thornbite Staff and its triggered abilities aren't strictly required for this specific mana-positive loop, the presence of the full assembly enables all sorts of recursive automation across Commander, Legacy, Oathbreaker, and Vintage formats.