Zinnia, Valley's Voice + Timestream Navigator + Cloudstone Curio

Zinnia, Valley's Voice

Timestream Navigator

Cloudstone Curio

How it works

1. Cast TImestream Navigator by paying 1, plus an additional 2 for its offspring cost.
2. If you control ten or more permanents and don't have the city's blessing, Timestream Navigator gives you the city's blessing.
3. When Timestream Navigator enters the battlefield, it and Cloudstone Curio trigger.
4. Resolve the Cloudstone Curio trigger, choosing not to return anything to your hand.
5. Resolve the Timestream Navigator trigger, creating a token copy of it that is 1/1.
6. If you control ten or more permanents and don't have the city's blessing, the Timestream Navigator token gives you the city's blessing.
7. When the Timestream Navigator token enters the battlefield, Cloudstone Curio triggers, returning the nontoken Timestream Navigator from the battlefield to your hand.
8. During your next turn, repeat steps 1 through 7 one additional time.
9. Activate the oldest Timestream Navigator token by paying 2, tapping it and putting it from the battlefield onto the bottom of your library, causing you to take an extra turn after this one.
10. Repeat from step 8.

This loop relies on Zinnia, Valley's Voice granting your creature spells offspring so that entering the battlefield triggers a cascade of value. With Cloudstone Curio sitting on the battlefield, the token copy created by that offspring ability triggers the Curio, allowing you to bounce the original Timestream Navigator back to your hand safely while leaving the token behind. Once you've secured the city's blessing, you can tap that token to take an extra turn, reset it to your library, and replay the original Timestream Navigator to repeat the process indefinitely for infinite turns.