[@Tyler]

If it helps at all we can just change the power to control over a small amount of dark matter energy. Really the only reason I used a dark/shadow based name for it is because I felt it the best single word description. In another summery the energy that causes Devin to be blind is in fact controllable; so with practice he can no longer be blind and apply the energy in another way such as having it explode from his hands or attach itself to another person (Causing them to go blind.) It is also important to note that this isn't a energy he can create a large amount of. He couldn't create a whole sword as this is energy that is "bottled" around his eyes. I have an idea that he can at the cost of his energy and health create a large amount, but I don't like having "O crap" buttons with powers.

Would that clear up the issue of it being labeled as a form of Umbrakinesis?