Romana II + Overlord of the Hauntwoods + Retreat to Coralhelm + Tireless Provisioner

Romana II

Overlord of the Hauntwoods

Retreat to Coralhelm

Tireless Provisioner

How it works

1. Cast Overlord of the Hauntwoods by paying 3.
2. When Overlord of the Hauntwoods enters the battlefield, it triggers, creating a tapped Everywhere land token.
3. When the Everywhere token enters the battlefield, Tireless Provisioner and Retreat to Coralhelm trigger.
4. Reoslve the Tireless Provisioner trigger, creating a Treasure token.
5. Resolve the Retreat to Coralhelm trigger, untapping Romana II.
6. Activate the Treasure by tapping and sacrificing it, adding 1.
7. Activate Romana II by paying 1 and tapping it, creating a tapped copy of the Everywhere token.
8. Repeat from step 3.

This clever loop relies on the constant stream of land tokens generated by casting Overlord of the Hauntwoods for its impending cost, which immediately triggers both Tireless Provisioner and Retreat to Coralhelm whenever a new Everywhere token hits the battlefield. Tireless Provisioner turns each of those landfalls into a usable Treasure token, while Retreat to Coralhelm untaps Romana II to keep her ready for action. You then use the mana from the Treasure to activate Romana II, copying that very same Everywhere token to restart the entire sequence.