Extravagant Replication + Returned Pastcaller + Time Warp

Extravagant Replication

Returned Pastcaller

Time Warp

How it works

1. Cast Time Warp by paying its mana cost, causing you to take an extra turn after this one.
2. Move to your next turn.
3. At the beginning of your upkeep, Extravagant Replication triggers, creating a token copy of Returned Pastcaller.
4. When the Returned Pastcaller token enters the battlefield, it triggers, returning Time Warp from your graveyard to your hand.
5. Repeat.

This looping setup turns your upkeep step into an engine for infinite turns. It starts when Extravagant Replication triggers at the beginning of your turn to create a token copy of Returned Pastcaller. As that token enters the battlefield, its triggered ability reaches into your graveyard to retrieve Time Warp, which you then cast to secure another turn—and because Extravagant Replication copies another nonland permanent each upkeep, you can repeat this exact cycle indefinitely to lock down the game.