Responses
Because He's a ticking bomb that will explode in any minute, hurting not only those around him but Aristia too.
He's a Yandere character, and those persons can't have "happy endings". There's simply no way He can make Aristia any good until He himself treat that mental disorder (and sadly enough, there wasn't any good way to treat it on those times. Psychology wasn't a thing lol)
so many people against Allen here and I'm secretly rooting for him tho I know he won't end up with her...tbh I wish she won't end up with Prince but we all know she will...