It was a low level dragons magic. THe one we saw in the last volume needed the combined magic power of Desir, Zod and the priestess, plus a lengthy incantation, and I believe that the large amount of magic power fried his eye.
I love what you're doing, your redrawing and translating is as good as any other high-quality scanlators, and you bring so many in one go. We all hope you continue!