spell effect-you cause ANY spell that dosn't get through your spell resitance to rebound back upon the caster of sead spell(obivouslly the spell that gets rebound dosn't originate from the same magi that has this spell cast upon him/her)this spell is goes up with the level of regovim that you have at the time of the casting
requisite-regovim general
target-ind.
range-personal
duration-sun(or until a spell is bouced off of you)
tell me what you think of this spell
Well, 2 thoughts:
- Mirror of Opposition (Form)
- Too many twilights
Isn't that what the night watchman said? 
It's OK, but would be in Muto instead of Rego as BoXer said.
Your idea is to change the target of the spell cast at you.
Also, the duration of "sun(or until a spell is bouced off of you) " causes some problem, as it should be casted into a Watching Ward spells.
Basically, you can't cast a spell and have it's effect come out on certain circumstance, the ArsM system doesn't make such spell easy to do, making it a ritual. Faery have duration until, but i'm not sure how that would apply (serf parma, I think I should call ? 
Twilights? But that would imply that Abe had the slightest knowledge or ability for (ars) magic(a). Allow me to doubt such a statement.
Also, I second the mirror of opposition thought.
Cheers,
Xavi