After activating this card's [Main] effect, do Digimon that later enter the battle area by being moved or played also gain this card's effect?

What happens when this card is revealed upon a security check?

A Digimon gains this card's effect and attacks. At such times, can I activate the [When Attacking] effect gained from this card's effect after the attacking Digimon digivolves by another effect?

I play this card, then play a Digimon. Does it receive this card's effect?

I use 2 copies of this card. When I attack with a Digimon, can I activate its When Attacking effect twice in a single attack, giving an opponent's Digimon -4000 DP?