Some of the class abilities don't list in their descriptions what level they're gained at, making it difficult to immediately judge what the will save DC is. In fact, since it's set for each ability, I'd suggest just listing the DC with each ability. This would also let you drop the will save bonus/penalties for the sensing and capstone abilities by just including them in the listed DC. I think the text makes it clear enough that Harrowings are supposed to provoke will saves, but it would be good to repeat that in the Harrowing section for clarity.

One thing that irks me a little bit is all the swift action abilities. Don't get me wrong, swift actions are awesome, but it seems like a serious trap to give out so many easily usable abilities that will all provoke will saves. It is a big part of the class, but I know as a player I'd absolutely hate to get screwed over when I'm using my "boost" (imbuing Touch on melee weapon) before even attacking.

Finally, I'm seeing a lot of awesome options for melee (enough for do-it-yourself Shoggoth), but I'm seeing absolutely nothing for area blasting or other spell-like effects. The easiest comparison for the class is Warlock after all, and Shadowed Soul is screaming for a Darkness SLA, for example. The Harrowings may not be the best place as they seem to be more for manifestations of beastiness rather than new applications of existing power, but maybe some feats at least. I'm also a little disappointed in Armored Will and Profane Transcendence. Armored Will is a tiny tiny bonus and won't stack with items while Bestial Armor takes the full bonus of the second most important stat for everyone and stacks with items. I'd give Armored Will the full monk treatment, or at least allow the full bonus. Profane Transcendence is just a waste, at most invalidating a couple minor spells and giving you immunity to fire or cold (which will overlap with your existing resistance). I'd sling out some DR/good and/or serious immunities.

And speaking of immunities, I'm surprised they don't eventually get immunity to mind affecting. Even Binders with their weak little soul-sharing can manage that.