Although I'm not too keen on a healer fulfilling such a role (although I'd still play it for aesthetic reasons alone), I would love a void mage of some sort, who consumes voidsent for power and can wield the sort of spells Voidsent magi and the Ascian Overlords use. Yes, it's a little on the darker side lore-wise, but to loosely paraphrase Arbert, dark, light, it doesn't matter, it's how you use it which counts. Also, although Voidsent are risky things to control, you are the WoL/WoD in the end, which alone should give you more power to bend such beings to your will, much like the Ascians can.

I like the idea.