Hero card

Mirror Room

SpellUsed once: what it does depends on when you cast it

Needs: Changeling, Valiant

Gives: Room

Not in winning lists yet: read from the card text and the graph

Build a deck with Mirror Room as the hero

Makes it work

Personify · Whiskervale Forerunner · Mouse Trapper · Flock Impostor · Nettle Guard · Veteran Guardmouse · Whiskerquill Scribe · Chitinous Graspling

Benefits from it

Unwilling Vessel · Infernal Phantom · Entity Tracker · Gremlin Tamer · Stalked Researcher · Scrabbling Skullcrab · Erratic Apparition

Use instead if you don't have it

Worldwalker Helm · Moonlit Meditation · Fractured Realm · Donatello, Gadget Master · Tunnel Surveyor · Simulacrum Synthesizer

Cards in the meta that answer it

Countersculpt (Azorius Control) · Inevitable Defeat (4-Color Control) · No More Lies (Azorius Control) · We Say Thee Nay! (Dimir Aggro)