My classpects on here are a little outdated, so I'll update them and reason through some of them
My au is split between two sessions, the Undertale players (who needed to scratch their session because of some skeleton they can't remember the name or face of), and the Deltarune players.
Kris, Their of Heart. I had an explanation somewhere, but they start with no agency or means of any self expression, and steal it back from the soul.
Susie, Knight of Life. This one's in the running to be changed. She's very Knight coded, but is kind of shifting away from that by being more open and honest. She's got the Knight trauma, sure, and would lay down her life for others and act like she shouldn't be a healer at all. Yes the aspect is based on her healing ability and how that's changed sue me. Or should I say Susie. Classpect I'm least confident on and will change but we ball.
Ralsei, Prince of Void. Let me grip you by the shoulders it's perfect thematically, narratively, aesthetically, all the good stuff. I might need a separate post for him alone. I'll definitely need that actually and supply images. But Void is everything Ralsei doesn't want to be. He wants to be something for others, he wants to heal the people around him, he wants to be the saving grace of the prophecy. Literally the definition of every Prince who ever wanted to not be the aspect they actually were. Eridan hated the though of his own blind belief, and tried to act like he himself destroyed any false faith, but when it came down to it, he believed in his white sciences and flawed morals without hesitation. Dirk hated the idea that every splinter he had was tied to him. He hated that his soul was inherently a bad person, and every splinters mistakes amplified that. He tried to convince his friends that Hal went to be his own unique person when he split off. But in the end, he couldn't escape that every version of him, was him. Ralsei wants to be his opposite aspect. Personally, I view Void and Life to be better classpect pairings than Void and Light, but it can work either way. Yes, those are the only two aspect pairings that I flipped around. I swear it makes sense.
Birdly, Page of Light. Pages usually try to embody their aspect, but do it cringely wrong. Tavros thinks that being independent means doing things without anyone's input, and by telling everyone that you're really independent all the time. Jake thinks that being like his action movie heroes (the ones that embody Hope and belief), means that he mustn't ever question anything because it'll make him less heroic, questioning or talking through anything in a not "manly" way. Both of them cause so many problems. This is the Birdly category. "I'm the smartest and the most deserving of the spotlight and the luckiest!! I don't need anyone's help because that's not what the popular people do! No one can ever know of my study buddy either. Since I'm the best... surely all the lady's just want me badly........ they all have secret crushes on me because I embody Light, and I have the misconception that that's what Light means!" When he does some digging and actually realizes that's not what Light is as a Page he becomes woke and badass.
Noelle, Heir of Hope. She's always believed in creepypastas, anything scary on the internet, and always has a certain belief on things. Her Hope isn't something she uses as a tool, it guides her. It's something that came naturally to her, after she joined the session and Dess wasn't there to stop all her blind belief. I made a comic on her being an Heir of Hope, and having what she believes is there guide her. Literal transformation into her aspect: she gains the wings from the Hope symbol. Angel wings, for her to fly away. Metaphorical: she believes Dess is okay. This doesn't change anything about her sister, but maybe. If Noelle believes hard enough, maybe she'll come back. Just once.
(I need a sixth Deltarune player but none of the cast would fit I swear I might make Mettaton not even a part of the UT group istg)
Toriel, Sylph of Space. Lowkey she gives Kanaya I kid you not. Nurser and has a bit of bark to her bite. Maybe I just think Sans x Toriel gives off Davejade. Am I wrong. I also haven't thought extensively on how this fits. But I feel like it does somehow.
Sans, Seer of Time. Oooh the Seer Falloff Arc™ is beautifullllll. Like imagine the Sans as we know him is going through the Seer arc of I don't want to use my powers that both Terezi and Rose went on. Also added angst of him looking though Time after everyone forgot about Gaster's existence. There's something missing in the timeline, a gap somewhere. What is it?
Undyne, Rogue of Blood. Not that confident or sure about this one but she brings the team together and makes everyone else friend pilled by stealing blood, metaphorical and physical, from her enemies. WEAKEST classpect here I'm sorry Undyne the undying.
Alphys, Prince of Doom. Opposite of aspect acting, the Doom of the amalgamates she's forsaken hurts her. Maybe works for the au. I just need to think about Alphas more.
Gaster, Lord of Mind. Originally I was going to make him just be a Lord naturally, but I thought having him connect his own server disk to himself and start a dead session in the middle of the UT session was too scrumptious to pass up >:). But yeah he messed everything up. Lord of Mind, and will influence the entire story ever. The way I'm planning on making dark worlds work is that each dark world is a different timeline that the characters jump to. And mister Lord of Mind Gaster made that with his powerful Mind powers of different timeline junk.
Mettaton, Knight of Breath. Ok this is the one I classpects most recently and might even remove Mettaton and just make him a helper of the players. He definitely has a role as a sprite though. For funzies.