An interesting idea. This would explain Sans feeling of responsibility to the underground to stop Frisk and be a good older brother. Sans would feel like he needed to be strong like his father and stand up to the bullies
Steve Rogers is always saving Bucky Barnes but maybe this time Bucky Barnes is back to saving him. <<<<<<< Don't worry, I just have something in my eye, like a twig, or you know, a branch. I'm not crying
"When you think about it, Chara is really the hero of the genocide run because they're the one who finally puts a stop to you and forces you to true reset. Especially how they tell you not to genoicide again if you do it a second time.