It can 'Negate the Summon or activation..' You can negate fusion spell/fusion gate activation/ritual spell, just do it when it's activation. If you're too greedy and wait to see which monster it is. Then it's effect of the card. It's already activated. Same as you twister econ lol.
I think special summoning a monster which is in your hand can be countered by CV.A good example is summoning Dark Necrofear and Sacred Phoenix of Nephthys in your hand, being summoned by the effect of Hand of Nephthys.
Anonymous
