Constellar Siat (Super Rare)

If your opponent controls a monster and you control no monsters, you can Special Summon this card (from your hand). Once per turn: You can target 1 "Constellar" monster you control or in your Graveyard, this card's Level becomes the current Level of that monster. This card cannot be used as an Xyz Material for an Xyz Summon, except for the Xyz Summon of a "Constellar" monster.