Rui Kamishiro used to be one of the most respected sorcerers of his Kingdom, but it all changed when for drastical reasons, he had to use dark magic, which plastered a curse on him. He's slowly losing his mind, he knows sooner or later he'll turn completely hostile and he'll have to get killed before he does. He lost a lot of friends, but Nene; a maid of the castle, and Tsukasa; a royal knight stuck to him.
Based on a thread made by @nightnness on twt