A humble suggestion:
1."Arcane Weapon / Arcane Repulsion" seems like a one-point-wonder to me.
2. Arcane melee build suggests me to take Spell / Aether with 1/1/1/5, because first two talents are aoe friendly-fire things (therefore needing 5 in Spellcraft), and the Aether Avatar is plain useless with melee orientation of Dark Priest.
So, may be you should consider giving Arcane Repulsion something like "at level 5 you can use "Arcane Weapon" talents in Aether Avatar form"... Well, it must be well tested, because it may become a little overpowered. But may not)
P.S.: Or, perhaps, Arcane Repulsion could give scaling arcane resistance - that will be tricky, but surely grant another reason to actually use that Spell / Aether first and second skills.
Those are some interesting suggestions. I actually gave Dark Priests the Arcane and Aether trees as a way to deal some non-Darkness damage and also to facilitate a more caster-focused build. However, now that I have added Dark and Malediction, you can make a caster-focused build without touching Arcane or Aether. I would really like it there was an Arcane melee build in there somewhere, I'm just not sure quite how I want to do that.
You've certainly given me something to think about, thanks for your feedback!
Humble and Life Manipulation are both use speed: standard. presumably they should be weapon/spell respectively?
The invisibility damage penalty seems to still be there on aura of unlight. iirc you said you wanted to get rid of it? it's crippling. (I mean, I oneshot celia by doing over 2k damage with blunt thrust, so I guess I could eat the penalty, but...)
Yup, I must have neglected to define speeds for those talents; I'll get that fixed.
I had thought about removing the damage penalty from Unseen when I first started coding the Unlight tree, but, up until then, I had never really played with Invisibility. After I did, I found it to be a lot more powerful than I had expected. So, I left the penalty in, starting a bit higher than standard Invisibility, and scaling down to about 35%. Unseen is meant to be primarily defensive, after all, and you can deactivate it any time you want.
However... after having time to do some more in-depth play testing, I found that once you get to the mid-game, when you are frequently faced with packs of mobs, the Dark Priest needs all the defense they can get, and having to turn off Aura of Unlight/Unseen to deal decent damage can leave you really vulnerable. It's not quite so bad if you're running a caster build with Unhealing, Dark and Malediction (since the damage penalty doesn't affect unhealing and can be reduced for Dark spells), but it really is crippling to a melee build.
I'm still hesitant to remove it completely, but it could probably stand to be reduced significantly without making it too unbalanced, considering the other costs associated with it.