5 official rulings from Bandai, last ruled Mar 28, 2024. Straight answers to how this card actually resolves.

Does this card’s <Security> effect activate even if it loses the battle against the attacking Digimon?
Yes, it activates at the end of the battle, regardless of outcome.
Ruled Mar 28, 2024
If I use this card’s <Security> effect to prevent my opponent’s currently attacking Digimon from attacking players, does the attack end immediately, or does my opponent get to perform their remaining security checks?
Even after using this card’s <Security> effect to prevent your opponent’s Digimon from attacking players, it only prevents them from declaring further attacks. The current attack proceeds normally.
Ruled Mar 28, 2024
My opponent uses this card’s <Security> effect to prevent one of my Digimon with <Piercing> from attacking players. If that Digimon attacks and deletes an opponent's Digimon and survives, do I still get to perform security checks with <Piercing>?
Yes, you do.
Ruled Mar 28, 2024
I have 11 or fewer Digimon in play, and my opponent activates this card’s <Security> effect, preventing all of my Digimon from attacking players for the turn. If I later play a Digimon with <Rush> during that same turn, can that Digimon attack players?
Yes, it can. This card’s [Security Effect] only affects Digimon that are in play at the time it’s activated.
Ruled Mar 28, 2024
If this Digimon attacks and is deleted in battle, does its <End Of Attack> effect activate at the end of the attack?
No, it doesn’t.
Ruled Mar 28, 2024
Got a line that uses Alphamon? Map it in the builder and share it with a link.
Questions and answers are Bandai's official rulings, collected and translated by the DigimonCardGame Wiki community and reused here under CC BY-SA. Card names and card text are © their respective publishers; Combalo is not affiliated with Bandai.