Mishra's Self-Replicator [Dominaria] Azra Assassin its ATK becomes double its

its ATK becomes double its current ATK

then make 1 Insect monster on the field either gain 500 DEF

and add that amount to the ATK of the other monster

You can only use this effect of "Golden Castle of Stromberg" once per turn

Set: XY: Base Set Type: Colorless Rarity: Uncommon

Mishra's Self-Replicator [Dominaria] Azra Assassin its ATK becomes double itsSet: Dominaria Type: Artifact Creature Assembly Worker Rarity: Rare Cost: {5} Whenever you cast a historic spell, you may pay {1}. If you do, create a token that's a copy of Mishra's Self Replicator. (Artifacts, legendaries, and Sagas are historic.) It has witnessed history's most significant events, one incarnation after another.