Temple of Beginnings

Q:I have 0 security cards. Can I activate this card’s [Main] effect and perform without adding a security card to the hand?

A:Yes, you can.

Q:In what order do a [Security] effect, "when [...] performs a security check" effect, and "when a card is removed from [...] security stack" effect activate when they trigger simultaneously upon a security check?

A:[Security] effects take precedence for activation. Upon a security check, a [Security] effect will immediately activate without pending activation. For other triggered effects, the turn player activates their effects first.

Q:What does this card's effect do, exactly?

A:This effect allows you to choose one of your Digimon with [Aegiochusmon] or [Jupitermon] in its name and place its top stacked card as your top security card.

Q:Can I use this card’s effect to place one of Digimon with [Aegiochusmon] or [Jupitermon] in its name that doesn't have any cards under it on top of the security stack?

A:No, you can't. Only 1 card isn't considered "stacked cards."