What if...

[Nash]

Number 62 had a Chaos Xyz Evolution? Here's what I'd call it:

NumberC62: Neo Galaxy-Eyes Prime Photon Dragon
3 Level 8 monsters
ATK 4500 DEF 4000
You can also Xyz Summon this card by using a "Number 62: Galaxy-Eyes Prime Photon Dragon" as the Xyz Material. (Xyz Materials attached to that card are also Xyz Materials on this card.)When this card has a "Number 62: Galaxy-Eyes Prime Photon Dragon " as any of its Materials, this card cannot be destroyed by battle. If this card attacks or is attacked during damage calculation on either players turn, you can detach 1 Xyz Material, and if you do so, activate one of these effects:
-This card gains ATK equal to the combined Ranks of all Xyz Monsters on the field x400, during the damage calculation only.
-This card gains the original ATK of the monster it is battling during damage calculation only.

[Lithium]

It would be broken...if Galaxy/Photon decks were actually considered competitive xD
Otherwise it's situational^

[Nash]

Wouldn't be broken since Prime Photon can already detach a material etc etc