Gallantmon: Crimson Mode

Q:Do cards trashed from my opponent’s security stack by this card's [When Attacking] effect activate their [Security] effects?

A:No, the cards weren't being flipped over by a security check, so their [Security] effects 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 their last 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.