Aisyle is the fear version of Elysia, they share the same set of powers but Aisyle is more in touch and in control of his powers. Probably because he's not on the verge on madness all the time but he does throw the occasional temper tantrum. The reason there is no opposite for Light&Dark is because they are opposites so they balance out.

And no, you weren't online while I wrote that post.