River Song + Anurid Scavenger + Time Warp

River Song

Anurid Scavenger

Time Warp

How it works

1. Cast Time Warp by paying 3, causing you to take an extra turn after this one.
2. Move to your next turn.
3. At the beginning of your upkeep, Anurid Scavenger triggers, causing you to put Time Warp on the bottom of your library from your graveyard.
4. Move to your draw step, drawing Time Warp from the bottom of your library due to River Song.
5. Repeat.

This brilliant loop locks down infinite turns by weaponizing Anurid Scavenger's upkeep tax to recycle Time Warp directly back into your deck, where River Song's bizarre replacement effect turns your draw step into a guaranteed retrieval of the extra-turn spell. While Anurid Scavenger ordinarily demands a graveyard sacrifice, you feed it the very Time Warp you just cast, and River Song bypasses the top of your library entirely so you draw it right back instead of missing it.