Progenitor Mimic + Returned Pastcaller + Time Warp

Progenitor Mimic

Returned Pastcaller

Time Warp

How it works

1. Cast Time Warp 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 Returned Pastcaller.
3. When the token Returned Pastcaller enters the battlefield, it triggers itself, returning Time Warp from your graveyard to your hand.
4. Repeat.

This recursive engine locks down the game by chaining infinite turns, leveraging Progenitor Mimic's steady stream of token generation to constantly feed your hand. Each upkeep, the Mimic pumps out a fresh token copy of Returned Pastcaller, whose entry trigger immediately plucks Time Warp right back out of your graveyard. Because Time Warp gives you the extra turns you need to survive and repeat your upkeeps, you can keep casting the spell every single turn without ever running out of resources.