Mirror Box [Kamigawa: Neon Dynasty Prerelease Promos] Ancient Dragon/Tem Warriors Whenever you attack with Merry

Whenever you attack with Merry and another legendary creature

Set: Sun & Moon: Lost Thunder Type: Psychic Rarity: Promo Retreat cost: 3

Other blue creatures you control get +1/+1

Set: Wilds of Eldraine Commander Type: Legendary Creature — Faerie Noble Rarity: Mythic Cost: {1}{U}{B} Flying

According to local legend

Mirror Box [Kamigawa: Neon Dynasty Prerelease Promos] Ancient Dragon/Tem Warriors Whenever you attack with MerrySet: 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.