User blog comment:KasuraS/Aldebaran and Ram/Rem's Past Theory/@comment-30772171-20161227072602/@comment-30677659-20161227133628

Just now, I have a new theory. Al was hired to kill Ram when she was still young. He lost his left arm, then he "killed" her. In that period, he should be early thirties. After that, the Witch Cult attempted the Oni village, but Ram survived and came back to save her twin sister Rem and lost her horn by protecting her. But when Al learnt Ram was still alive, he expressed his disgust because he failed to kill her and lost her left arm for nothing.