Constellar Siat

Level 1 LIGHT/Fairy Effect
100 ATK / 1600 DEF

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.

Rulings – Yugipedia

Printings:

Duel Terminal 7b: DT07-EN065 (Duel Terminal Normal Parallel Rare) - 2013-02-01
Hidden Arsenal 7: Knight of Stars: HA07-EN041 (Super Rare) - 2013-04-26

Prices:

Cardmarket: 0.18 €
TCGplayer: $ 0.18