Evilswarm Coppelia — Ruling

Regola generale

Regarding the『when this card leaves the field because of your opponent』effect:
This is a Trigger Effect that activates when this card leaves the field. (Activating it is mandatory.)
This effect will activate when your opponent causes this face-up card, which you own, to leave the field and be added to your hand, sent to your Graveyard, or banished face-up, while under your control. It will also be activated if your opponent causes this face-down card, which you own and control, to leave the field and be sent to the Graveyard, or banished face-up. (It will not be activated if this card is returned to the Deck, or is banished face-down. It will also not activate if this card, which you own, leaves the field while your opponent controls it.)
This effect will not be activated if this card, which is face-down on the field, returns to your hand. (The exception is if your hand is currently being revealed, in which case the effect will activate.)
It also activates during the Damage Step.
When you activate this effect, if there are any face-up monsters in your opponent's Monster Zone, choose one of them as the target. If there are none you can choose, the effect will not be applied.
Returning control of the monster during the End Phase does not start a Chain.