Aegaion the Sea Castrum — Ruling

Effetto 1

About this card's ① st effect:
This effect is a Quick Effect, which can be activated in the Monster Zone.
You can also activate it during the Damage Step, from the Start of the Damage Step to Before Damage Calculation.
If a monster with "?" ATK is banished by this effect, this card's ATK becomes zero.
Banishing a monster from your opponent's face-down Extra Deck, and this card's ATK becoming equal to the banished monster's ATK, are treated as having happened simultaneously.
This effect can also be activated during the Damage Step. (It can be activated from the start of the Damage Step, before damage calculation.)

About this card's ② nd effect:
This effect is a Quick Effect, which can be activated in the Monster Zone.
To activate this effect, detach 1 material from this card as a cost.
You cannot activate it during the Damage Step.
If the『return it to the Extra Deck』effect is successfully applied, you then apply the『destroy 1 monster your opponent controls with the same monster card type (Fusion, Synchro, or Xyz)』effect. (These are treated as having been done simultaneously.)
To activate this effect, detach 1 Xyz material from this card as a cost.