2006-02-01 : If your opponent discards any cards during their cleanup step to get down to the maximum hand size, the ability will trigger and players will receive priority. After that cleanup step ends, a new one will begin and Abyssal Nocturnus's effect will end. It won't carry over into the next turn.

2006-02-01 : If your opponent discards multiple cards to a single effect, this will trigger multiple times.