I'd love any feedback anyone would like to offer, and I should first warn that this class is currently unplaytested. It goes from levels 1 through 10, and features a few bonus feats and a new monster (usable by the class as a familiar).
Some thoughts:
Command the Dead should be at least an encounter power, probably a daily. It's that good. In fact, maybe it'd be better as a level 9 or higher daily attack power instead of a class feature. A class feature would need to be something much less powerful. You could make it similar to a fighter's mark - or better yet, like a paladin's divine challenge: you can use a minor to "mark" an undead and it has penalty to attack you and takes damage if it does.
Command the Dead
You exert your will over the living dead.
At-Will ✦ Arcane
Minor Action Close burst 5
Target: One creature with the undead keyword in burst
Effect: You mark the target. That creature takes a -5 penalty to attack you and if it succeeds on an attack that damages you, it takes damage equal to your Wis modifier + 3. This effect lasts until the beginning of your next turn. You can use Command the Dead once per turn.
Sure, it's restricted to undead-only, but you only have to be close to it and the penalty is severe. That's still way less powerful than dominating every round. Of course, it's a sort of silly penalty in some ways - minus to attack and THEN you take damage - but still, it's the general idea.
Manipulate Life - I also like the idea about making the "necro's healing word" power a bit different, too. Pulling a healing surge from a monster is also a bit too powerful, since healing surges are so good and monsters can't use them. I like the version eleventh presented, but I would just make it even more like Healing Word - 2 times per encounter, pull a surge from yourself or willing ally and send to an ally within range. Simple enough.
Disperse the Fleeing Soul - Personally, I would re-do so that it isn't a weapon power, but maybe that's just me. Also, you're pretty much giving an at-will power that's the same as the level 5 weapon power... except it also works on everyone in range? That's awfully strong. I'd limit it to either 1 temp for everyone in range, or Int temps for yourself. Maybe Int temps for an ally in range.
Fester - 1d10 is also a tad strong for an at-will, even if it doesn't do anything else and is limited in targets. It'd be better to throw an effect on it and reduce the die to d8 or something like that, in my opinion.
Lesser Shadow's Drain - Should this be a weapon attack since it targets AC? Otherwise you'll have a hard time hitting. Also 1/2 damage is not the best mechanic because you can use items/other powers to up damage. Maybe just Int temps again?
Talons of Darkness - Did you mean this to be a weapon one as well? Also a d8 seems strong to me.
That's as far as I got, but overall I'd say the flavor is awesome, the ideas are awesome, but everything is either a bit too powerful or way too powerful. That might be just me, though.
