*barges in with popcorn* If a Spell is used on you, your opponent suffers the effects from it instead of you *barges out with popcorn*
Oppnent means the person who casted a spell on you, not your dueling opponent. I should have worded Protego clearer. Protego and Explliarmus only work when you've bene the target of a spell and have one of those spells. Here is an example:
Student A has Protego.
Student B casts Crucio on Student A.
Student A uses Protego on Student B, since that was the person who cast the spell on Student A.
No other targets may be selected with Protego or Expelliarmus.
Besides, it was after the deadline that the spell was cast, so points aren't wasted since it doesn't count.