1.The base stats of this weapon should be buffed significantly.(armor and hp)
2.The proc should stack atleast 35 armor and it should stack on each hit a warrior takes rather than the other way around.
3.The damage caused by the explosion of shield should be increased and it should heal the warrior for 20% hp and provide a armor buff to surrounding players.
4.A stun with the explosion wouldnt hurt either.

I know that all these suggestion may seem a bit too much but considering the current state of warriors these buffs may still not be enough.

Please feel free to state your suggestions.