Mirror Box [Kamigawa: Neon Dynasty Prerelease Promos] Ancient Dragon/Tem Warriors Set: Black & White: Legendary

Set: Black & White: Legendary Treasures Type: Psychic Rarity: Ultra Rare Retreat cost: Colorless

Discard a card: Proliferate

Other blue creatures you control get +1/+1

{T}: Each player gains control of all creatures they own

Whenever you attack with Merry and another legendary creature

Mirror Box [Kamigawa: Neon Dynasty Prerelease Promos] Ancient Dragon/Tem Warriors Set: Black & White: LegendarySet: Kamigawa: Neon Dynasty Prerelease Promos Type: Artifact Rarity: Rare Cost: {3} The "legend rule" doesn't apply to permanents you control. Each legendary creature you control gets +1 +1. Each nontoken creature you control gets +1 +1 for each other creature you control with the same name as that creature.