Illyx

he just love her too much that he didn't realize her suffering due to his special treatment. and sure, he left but he didnt know he left that big impact in her life since he believe she didnt love him as much as he did.

sure what he did is bad but not that unforgiveable, make it make sense, as if you never make a mistake? he did a mistake and he acknowledge it after she confront him and talk about it, he's not that self-centered.