"Bounty Hunter" Mastery Rework Idea

http://s13.postimg.org/b0yy35zxz/Bounty_Hunter.png

Grants +1 AD and +2 AP every 3 champion kills, or +2 AD and +4 AP every unique / shutdown champion kill.

I think this is more interactive, fun to use, and can help out with making comebacks. Also rewards skilled players with difficult tasks such as getting shut down kills or killing a champion who they have not yet killed. The numbers could be tweaked, although I think they are fair.