Aziel loved her, he trusted her, gave her all his love and provided her with anything in need, only in return, she betrayed him. Their relationship was all fake, she didn't love him in the first place but used him, technically, they are enemies, the user, who he had loved, was his enemy all along. Only then, Aziel couldn't help but feel his soul shattered after finding out, because his feelings were... but hers, was fake.