Niko, Light of Hope + Timestream Navigator + Thassa, Deep-Dwelling

Niko, Light of Hope

Timestream Navigator

Thassa, Deep-Dwelling

How it works

1. Activate Niko by paying 2 and tapping it, exiling Timestream Navigator and causing Shards you control to become a copy of Timestream Navigator until the end step.
2. Activate a Shard 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.
3. At the beginning of the next end step, Timestream Navigator is returned from exile to the battlefield. Thassa then triggers, blinking Niko.
4. When Niko enters, it triggers, creating two Shard tokens.
5. Repeat each turn.

By using Niko, Light of Hope to temporarily exile Timestream Navigator, we turn our Shard tokens into literal copies of the Navigator that are ready to take extra turns. Once those Shards-turned-Navigators shuffle themselves away to activate that extra turn, Thassa, Deep-Dwelling quietly holds the engine together by blinking Niko at the end of every turn cycle. This reset brings fresh Shards into existence, allowing you to seamlessly repeat the entire loop indefinitely as long as you've achieved the city's blessing.