[@Octo]

Yes and no. It is possible to have Darkness powers naturally, without just being afflicted with the Curse of Fendel. However, since it's not documented or understood, there are no Darkness Incantations, since there isn't any sort of common knowledge to draw on to create spells.

For this reason, most people who end up being born with a Darkness affinity can't actually [i]do[/i] anything with it, beyond maybe some weird shit happening passively around them when their emotions are running high. The average person doesn't have the sheer discipline/reserves of inner strength needed to manifest an Aura, and, without Incantations to guide the power instead, there's no real option for consciously controlling it.

Hypothetically, of course, there's also the option you mentioned of inheriting both the affinity of Darkness and the power of Aura, but, uh... that would [i]probably[/i] mean you're the Successor of Fendel, and thus a reincarnation of the guy who nearly conquered/destroyed the world.

And that's not to say it's not a fun concept, don't get me wrong -- it's just that I kind of already have plans for the Successor, Fendel, and his role in the plot. >_< So I think I'm gonna have to veto Darkness Aura as a playable power, unfortunately.