Kotis, Sibsig Champion + Altar of Dementia + Salvager of Secrets

Kotis, Sibsig Champion

Altar of Dementia

Salvager of Secrets

How it works

1. Cast the extra turn spell by paying its mana cost, causing you to take an extra turn after this one.
2. Move to your extra turn.
3. Activate Altar of Dementia by sacrificing Salvager of Secrets, causing you to mill cards equal to Salvager of Secrets's power.
4. Cast Salvager of Secrets from your graveyard by paying its mana cost and exiling three other cards from your graveyard, ensuring not to exile the extra turn spell.
5. When Salvager of Secrets enters the battlefield, it triggers, returning the extra turn spell from your graveyard to your hand.
6. Repeat.