Galactic Spiral Dragon

“While this card is in your hand or GY, if you control 2 or more LIGHT and/or DARK Dragon monsters: You can Special Summon this card in Defense Position, but banish it when it leaves the field. During your Main Phase: You can make all monsters you currently control become Level 8, until the end of this turn. You can only use each effect of "Galactic Spiral Dragon" once per turn.”