Hero abilities

[Sir Baron]

My suggestions: 

Probably won't happen but it could be fun hehe.

Royal Guard, Pavise: Emergency shield repair, restore equipped shield to 50% hp. 
Zwei, Sentry, Marauder: Crush through with weapon equipped when activated for x seconds
Legio, Sentinel, Aventurier: Increase weapon speed and prevent stagger from a block for x seconds
Juggernaut, Ranger, Halbadier: Reduce incoming damage by an additional % for x seconds.
Warden, Chosen, Master peltast: Multishot, multiple projectiles shot/thrown at once.
Repeaterman: Instantly reload your clip.
Hoplite: Shield bash.

You would have to make the RG/PC one like 5 minute recharge or it would just be to OP
I can take most any wave for over 2 minutes without changing shields
On the other hand it could be a ton of fun done right