Progenitor Mimic + Walk the Aeons + Revolutionist

Progenitor Mimic

Walk the Aeons

Revolutionist

How it works

1. Cast Walk the Aeons by paying its mana cost, taking an extra turn after this one.
2. At the beginning of your next upkeep, Progenitor Mimic triggers, creating a token copy of Revolutionist.
3. When the token Revolutionist enters the battlefield, it triggers itself, returning Walk the Aeons from your graveyard to your hand.
4. Repeat.

This clever loop achieves infinite turns by recycling a single copy of Walk the Aeons indefinitely. The engine is anchored by Progenitor Mimic, which uses its upkeep trigger to continuously spawn fresh token copies of Revolutionist without ever being a token itself. Each time a new Revolutionist token enters the battlefield, its triggered ability reaches into your graveyard to pluck back Walk the Aeons, neatly bypassing any need for the spell's costly buyback requirement.