It was either my Floaters team or my DMS-VG one, but there are some spoilery things I'd rather not risk revealing with the latter, marriage aside obvs, plus I don't think that cringe-fest you linked there has a Sue to begin with. For the sake of simplicity, I could have just Lilac help out with this one, since I'm busy with Real Life as it is and would probably be best suited as a beta reader with just one of my characters included. That and, well, the poor girl just needs to show up more IMO. :P

My e-mail is clickable if you're interested in bringing me in. I've played Undertale all the way to the Pacifist ending and know the lore well enough, though I haven't looked into Deltarune just yet (I do wish to, though). If I somehow miss any canon knowledge, though, I can always use the wikia to help with that!