Hmm.. I scrolled through the skills in the Complete save and a few things caught my eye -
Matrydom - Seems a tad too strong, since it is 100% Add:Dead and does Shock! damage. I think some other negative status like Death Sentence would be better than Dead, it would make it a lot more situational. I could see myself going with Matrydom even at full health because it one-shots most units and there aren't many revival skills.
Explosive Shot (sniper skillset) - If I'm not reading the formula wrongly, it does PA * (1...10) damage, similar to Throw Stone, and has a 100% knockback. I don't see it as being very useful though, the damage is quite low and knockback doesn't work most of the time. Fall damage is also quite negligible. Maybe rewire it to be similar to Sonic Boom from the FFTA Hunter, but make it cost MP?
Arise (devout skillset) - This skill seems a tad too powerful, even if it has a whopping 9 CT. Doesn't seem that clear-cut though, I still don't know what the Fire element is supposed to do, other than for flavor. Infinite AoE Target All Allies revival seems a little too good to be true.
Harbinger - You've probably realised this by now, but Harbinger has duplicates of Fear, Stop, Immobilise and Disable in its' skillset. Fleshrender and Fearsyphon don't seem good enough to justify the JP spent on them, as it is only a PA*2 damage increase from what I'm seeing. You could probably give them 3-4 range to provide an alternative over normal attacks on Immobilised / Disabled targets.