I imagine it would be a little bit OP if you wouldn't get blinded by any type of Darkness. Especially if you take the absurdly good & cheap "Misty Step" of the Shadow Sorc into account. However, I agree that it is extremely confusing that the icons of the special Darkness and the normal Darkness look almost identical. That tiny metamagic flame in the center gets lost when it's just a small icon on your hotbar. I would help if it it was a bit more purple or something.
