"ermahgerd he changed DmK!"
That made my day! Haha. Anyways, I use most, I don't really use the buff against undead, or weaken to darkness. I also don't use Favor. I have used Void, and I haven't used Revert. I do, however, use the rest of the skills. Im level 64, and I have 130 STR, 130 WIS, 45 END, and 10 LUK. So, I couldn't tell you why you are running out of Mana so quickly.
@Ash, I probably should ask, is there anything planned for possible items to match the DmK armor in the near future? Or are we just stuck with what there currently is? Don't get me wrong, I am really happy with the class!