Marina Vendrell + Mirror Room // Fractured Realm + Kelpie Guide + Yarus, Roar of the Old Gods

Marina Vendrell

Mirror Room // Fractured Realm

Kelpie Guide

Yarus, Roar of the Old Gods

How it works

1. Activate Marina by tapping it, unlocking Mirror Room.
2. Mirror Room triggers twice due to Fractured Realm, creating two token copies of Kelpie Guide.
3. Activate one of the Kelpie Guide tokens by tapping it, untapping Marina.
4. Activate Marina by tapping it, locking Mirror Room.
5. Activate the other Kelpie Guide token by tapping it, untapping Marina.
6. Repeat.

This brilliant loop hinges on the doubling power of Mirror Room // Fractured Realm's Fractured Realm side, which ensures that unlocking its other door triggers twice to flood the board with two token copies of Kelpie Guide instead of one. Once those copies hit the battlefield, you can use one Kelpie Guide to untap Marina Vendrell, use Marina's tap ability to lock and unlock the Room, and then use the second Kelpie Guide to untap Marina again. Because Yarus, Roar of the Old Gods is also part of the setup, all these entering creatures and their associated triggers can spiral completely out of hand, turning your room-management engine into an endless wave of permanent tokens.