Timestream Navigator + Riptide Laboratory + Archmage of Echoes

Timestream Navigator

Riptide Laboratory

Archmage of Echoes

How it works

1. Cast Timestream Navigator by paying 1.
2. Archmage of Echoes triggers, copying the Timestream Navigator spell.
3. Resolve both Timestream Navigator spells.
4. If you don't have the city's blessing, either the Timestream Navigator token or the nontoken Timestream Navigator gives you the city's blessing.
5. During your next turn, activate Riptide Laboratory's second ability by paying 1 and tapping it, returning the nontoken Timestream Navigator to your hand from the battlefield.
6. Activate the ability of the Timestream Navigator token by paying 2, tapping it and putting on the bottom of your library, causing you to take an extra turn after that one.
7. Repeat.

This brilliant loop hinges on leveraging Timestream Navigator alongside Archmage of Echoes, which duplicates your Wizard spell upon cast so you can easily secure the city's blessing and maintain redundancy on the battlefield. Once your board state is established, Riptide Laboratory steps in to safely bounce your original Timestream Navigator back to your hand for only {1}{U}, bypassing the token's self-sacrificing bottom-of-library clause. Meanwhile, the Timestream Navigator token spends its activation to grant you endless extra turns, locking down the game through a continuous cycle of casting, bouncing, and taking the helm of time itself.