Unformed Void

Level 4 LIGHT/Aqua Xyz Effect
0 ATK / 0 DEF

3 Level 4 monsters
Once per turn, during your opponent's Main Phase: You can detach 1 Xyz Material from this card; this card gains ATK and DEF equal to the total ATK of all face-up Xyz Monsters your opponent currently controls (this is a Quick Effect).

Rulings – Yugipedia

Printings:

Number Hunters: NUMH-EN049 (Super Rare) - 2013-07-12

Prices:

Cardmarket: 0.15 €
TCGplayer: $ 0.11