"Nova
Cost 6

Whenever Nova attacks, you may discard a Spider-Friends character card from your hand. If you do, Nova gets +X ATK this attack, where X is the cost of the card you discarded.
"


...ok, so quick question... can you discard your whole hand of spider friends characters and give nova like a gajillion (prounounced GA-jill-ion) attack... or just one spider friends card and give him something like +8. Yes, yes yes... i know you can overload him... but honestly, who runs overloads anymore. I might if you can discard a bazillion cards to get a gajillion attack bonus... stupid nova ...

Nova triggers only once when he attacks.

The effect gives you the option of discarding a card, not any number of cards.

So in summary: no, you cannot discard your entire hand in order to pump Nova.

thanks for the clarification... time to go beat up my brother...