There are no cards that can negate a Fusion Summon. All Fusion Summons happen during the resolution of an activated effect. You can't activate an effect during the resolution of another, and once the effect resolves, the Summon was already successful and can't be negated.
Ahh, I see.
So Obelisk's summon can be negated because the card summon itself, whereas Quintet is summoned by another card. So champion vigilance cannot select Quintet as a target of it's negation.
So complicated, and to think some people call Yu-Gi-Oh a child's game
Anonymous
