Conduit of Worlds + Time Stretch + Salvager of Secrets + Ashnod's Altar

Conduit of Worlds

Time Stretch

Salvager of Secrets

Ashnod's Altar

How it works

1. Activate Ashnod's Altar by sacrificing Salvager of Secrets, adding CC.
2. Cast Time Stretch by paying 8, causing you to take two extra turns after this one.
3. Move to your first extra turn.
4. Activate Conduit of Worlds by tapping it, causing you to pay 3 to cast Salvager of Secrets from your graveyard.
5. When Salvager of Secrets enters the battlefield, it triggers, returning Time Stretch from your graveyard to your hand.
6. Move to your second extra turn.
7. Repeat.