Re: AJ Leader of Shield
Punk and/or Heyman is the leader of The Shield.
The whole "injustice" thing is an excuse for them to protect and help CM Punk without as harsh of a backlash by the management or fans (and yes, I'm speaking in kayfabe terms when I speak about the "management", obviously).
They don't actually shield the WWE from injustice, they just shield Punk from basically anything by attacking everyone who's a threat to go over him. It isn't a coincidence that 90% of their appearances attack people who Punk was beefing with. The only strange one was Orton, which seemed like little more than a chanegup thrown so it didn't solely just benefit Punk and be too obvious.
I don't know what the deal with AJ and Ryblack is though. Hopefully it isn't just what it seems like. . .yet another filler fued for Cena while he waits for CM Punk to conclude his next fued and lose the belt, then Cena will go for the belt again.