>I'm wondering if anyone has other good ideas for special abilities of these
Just some ideas to get you going...
Detecting people that don't conform to their idiology; alternatively,
detecting people actively opposed to same.
Resistance/immunity to mind effecting spells, or just charm/compulsion
suggestion/charm effects to "convert" people to the cause if it's a
"leader" style class.
rage, or frenzy, or related effects.
The Die Hard feat, to allow them to keep fighting the enemy longer.
Aura of Hallow/Unhallow
Ability to attack as an aligned weapon
Soylant Clear: Clearly less people, Clearly less fat.