Gallantmon

Q:I use this card's When Attacking effect to trash my opponent's Security Cards. Do the security effects on those cards activate?

A:No. They weren't flipped over in a security check, so they don't activate.

Q:My opponent has 1 or more cards in their security stack. I attack my opponent with this Digimon and its When Attacking effect trashes the rest of their security cards, leaving them with zero cards in their security stack. If the attack isn't blocked and my attack is successful when they have zero cards in their security stack, do I win the game?

A:Yes, you do.