[quote=@Menhir]
[@Ryik]
So I googled that card you used, and it said you can't activate Crush Card Virus during the damage step?
So how does that work, exactly?
[/quote]
I couldn't find what you were talking about, but I don't believe it matters.

Every time you attack with a monster during the battle phase, you first "declare the attack" before the damage step happens. It is during this time that your opponent can still activate cards like Negate Attack or Crush Card Virus in response.

To be activated during the damage step usually only makes a difference when you want the attack target to be flipped face-up, which can be important for, for example, [url=http://yugioh.wikia.com/wiki/Sealing_Ceremony_of_Mokuton]Sealing Ceremony of Mokuton[/url], flip effects like Man-Eater Bug or continuous effects like Jinzo.