Mystic Sanctuary + Dust Bowl + Ancient Greenwarden + Time Warp

Mystic Sanctuary

Dust Bowl

Ancient Greenwarden

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. Activate Dust Bowl by paying 3, tapping it and sacrificing Mystic Sanctuary, destroying a nonbasic land.
3. Play Mystic Sanctuary from your graveyard.
4. When Mystic Sanctuary enters untapped, it triggers, putting Time Warp from your graveyard onto the top of your library.
5. Move to your next turn, drawing Time Warp during your draw step.
6. Repeat.

This elegant loop achieves near-infinite turns by recycling a single copy of Time Warp straight back to the top of your library. The engine is powered by Ancient Greenwarden, whose static ability allows you to repeatedly play lands from your graveyard while simultaneously doubling the enter-the-battlefield trigger of Mystic Sanctuary. Because Mystic Sanctuary returns Time Warp to your library when it enters untapped, you can then sacrifice the Sanctuary to Dust Bowl, sending it back to the graveyard so Ancient Greenwarden can let you replay it on your next turn.