Board Thread:General Discussion/@comment-26849575-20160315015552/@comment-27701762-20160315030433

Would he feel bad? Absolutely. Would he have a change of heart? No, given that he feels he needs to take their souls for the good of his people.

It's not entirely clear if Asgore is the one who killed the previous children. It's certainly possible that he did, but it's never explicitly stated. He could very well have just hoped that the other monsters would take care of it for him, and then collected the soul once the deed is done. In either case, Asgore has made his decree because he believes he has to do it, and in some sense he has forced himself into a corner in the first place.

Which certainly leaves open the possibility that the previous kids were all innocent.