Romana II + Mutable Explorer + Retreat to Coralhelm + Nissa, Resurgent Animist

Romana II

Mutable Explorer

Retreat to Coralhelm

Nissa, Resurgent Animist

How it works

1. Cast Mutable Explorer by paying 2.
2. When Mutable Explorer enters the battlefield, it triggers, creating a tapped Mutavault land token.
3. When the Mutavault token enters the battlefield, Nissa and Retreat to Coralhelm trigger.
4. Reoslve the Nissa trigger, adding 1.
5. Resolve the Retreat to Coralhelm trigger, untapping Romana II.
6. Activate Romana II by paying 1 and tapping it, creating a tapped copy of the Mutavault token.
7. Repeat from step 3.

This clever setup revolves around capitalizing on the land tokens generated by Mutable Explorer, which enters the battlefield to start the chain. Every time a new land token appears, Retreat to Coralhelm triggers to untap Romana II, while Nissa, Resurgent Animist simultaneously fuels the loop by providing the mana needed to activate Romana II's ability. Romana II then creates a fresh copy of that land token, repeating the landfall cycle indefinitely to flood the board with an endless sea of land duplicates.