Requires

Feldon of the Third Path must be on the battlefield. Atsushi, the Blazing Sky must be in the graveyard. Thornbite Staff must be on the battlefield. Phyrexian Altar must be on the battlefield. Thornbite Staff attached to Feldon. Feldon does not have summoning sickness. Mana needed:

Steps

1. Activate Feldon by paying and tapping it, creating a token copy of Atsushi with haste.
2. Activate Phyrexian Altar by sacrificing the Atsushi token, adding .
3. Atsushi dies, triggering itself and Feldon.
4. Resolve the Atsushi trigger, creating three Treasure tokens.
5. Resolve the Feldon trigger, untapping it.
6. Activate two Treasure tokens by tapping and sacrificing them, adding .
7. Repeat.
8. Once you have infinite mana, you may instead exile cards using Atsushi and cast them from exile this turn.

Results