9 official rulings from Bandai, last ruled Sep 20, 2024. Straight answers to how this card actually resolves.

If I don't have a level 4 or lower purple or yellow Digimon card in my trash, do both players still trash the top card of their security stack from this card's <When Digivolving> effect?
Yes, they do.
Ruled Mar 28, 2024
Do the <Security> effects on cards trashed by this card's <When Digivolving> effect activate?
No, they don't.
Ruled Mar 28, 2024
If I activate this card's <When Digivolving> effect when my opponent has an empty security stack, do I win the game?
No, just because there are no security cards to trash doesn't mean you win the game.
Ruled Mar 28, 2024
If either or both players have empty security stacks, can I use this card's <When Digivolving> effect to play a level 4 or lower purple or yellow Digimon card from my trash?
Yes, you can.
Ruled Mar 28, 2024
Which cards can be played by this card's [When Digivolving] effect?
One "Purple Lv.4 or lower Digimon card" or "Yellow Lv.4 or lower Digimon card".
Ruled Sep 20, 2024
Does the [When Digivolving] effect of this card activate the security effect that the card you trash has?
No, it does not activate.
If this card's [When Digivolving] effect is activated when the opponent has 0 security, does it win the game?
No, just because you cannot trash a security card does not mean you win the game.
If this card's [When Digivolving] effect is activated when I or my opponent or both have 0 security, can I still play a purple or yellow Lv.4 or lower Digimon card from my trash without paying cost?
Yes, you can play.
Does this card's [When Digivolving] effect trash one of each other's security from the top, even if there is no purple or yellow Lv.4 or lower Digimon card in my trash?
Yes, please trash.
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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.