Timestream Navigator + Cellar Door + Celestine, the Living Saint

Timestream Navigator

Cellar Door

Celestine, the Living Saint

How it works

1. Activate Timestream Navigator by paying 2, tapping it, and putting it on the bottom of your library, causing you to take an extra turn after this one.
2. Activate Cellar Door by paying 3 and tapping it, targeting yourself, putting Timestream Navigator from the bottom of your library into your graveyard and creating a 2/2 Zombie token.
3. Declare Celestine as an attacker, dealing 3 damage and gaining 3 life when she does combat damage.
4. At the beginning of your end step, Celestine triggers, returning Timestream Navigator from your graveyard to the battlefield.
5. Move to your next turn.
6. Repeat.