Face the Great Beast! Galaxy-Eyes Tachyon Dragon

LIGHT

2 Level 8 monsters Once per Battle Phase, at the start of your Battle Phase: You can detach 1 material from this card; all other face-up monsters currently on the field have their effects negated, also their ATK/DEF become their original ATK/DEF, and if you do any of these, during the Battle Phase this turn, each time an opponent's card effect resolves, this card gains 1000 ATK until the end of the Battle Phase, also, it can make a second attack during each Battle Phase this turn.

LIGHT 4

If your opponent controls a face-up Xyz Monster, you can Special Summon this card (from your hand). If you do, this card's Level becomes 8.

Spell Normal

Target 1 face-up Xyz Monster you control; Special Summon from your Extra Deck, 1 "Number C" or "CXyz" monster with the same Type as that monster you control but 1 Rank higher, by using it as the Xyz Material. (This Special Summon is treated as an Xyz Summon. Xyz Materials attached to it also become Xyz Materials on the Summoned monster.) Then, if possible, detach 1 Xyz Material from a monster your opponent controls and attach it to the Summoned monster as an Xyz Material.

LIGHT 8

If you control a Level 8 monster, you can Normal Summon this card without Tributing.