Make it so that you can't be staggered AT ALL in Revenge Mode.
Centurion's kick and stun abilities are only overpowered in a gank situation. If Revenge Mode was tweaked so that things like Warden's shoulder bash, Nobushi's kick or Centurions punches (charged and uncharged) would simply bounce off of you, the game as a whole would be far better. If this happened, Centurion's pins after charged attacks wouldn't leave you completely vulnerable to free damage from absolutely everyone and his kick spam would become ineffective.
Thoughts?
Perhaps just giving Revenge Mode uninterruptible stance at all times? I'm not sure if that would make it overpowered again, but in a gank situation not being able to be staggered is HUGE. It means you can focus on taking down one target at a time or just swapping targets in between hits since they won't be prepared for it.
Centurion says "F*** that" and stuns someone with a charged heavy, or a kick, or an unblockable stab and that person is pretty much dead to rights immediately. Since that person can't activate revenge mode immediately and his teammates can wail on them in the meantime.