Bujin Regalia - The Jewel

Kartentext

Target 1 Rank 4 Xyz Monster you control; equip this card to that target. It gains 300 ATK for each Xyz Material attached to it. Once per turn, while this card is equipped to a monster by this effect: You can attach 1 "Bujin" monster from your hand to the equipped monster as an Xyz Material.