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

If an opponent's attacking Digimon has the [Deva], does this card's <Opp Turn> effect activate?
No. It activates when the security card revealed by a security check is a Digimon card with the [Deva].
Ruled Mar 28, 2024
If the card revealed for a security check is a Digimon card with the [Deva], can I choose to not activate this card's <Opp Turn> effect and not play that Digimon, but still battle with my opponent's attacking Digimon?
No, you can't. This card's effect reads "play it," therefore you must activate it when the card revealed for a security check is a Digimon card with the [Deva].
Ruled Mar 28, 2024
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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.