deltarune

"Deltarune is a role-playing video game developed by Toby Fox. The player controls a teenage human, Kris, who is destined to save the world together with Susie, a monster, and Ralsei, a prince from the Dark World. During their quest to seal the "Dark Fountains", the group meet the inhabitants of the "Dark World", some of whom try to stop them. The combat system is based on bullet hell attacks the player must dodge. Similar to Undertale, enemy encounters can be resolved peacefully or through violence." -Wikipedia.

 Deltarune's Relationship with Undertale Now Deltarune's relationship with Undertale is a bit funky as we don't know if it is a sequel or a predecessor thanks to Toby Fox being vague as always but thanks to JaruJaruJ's theory on it they have managed to come to the conclusion that it is most likely is an Alternate Timeline where the monster war didn't happen or it ended with monsters being on the surface.

With this we know that all the Undertale characters that are in Deltarune are the same as their Undertale versions until a certain point where they split into different characters.

If Deltarune is truly an alternate timeline why are there new characters that we didn't see in Undertale? Well, if we look at the gravestones in Deltarune we can see Gerson is dead, so Deltarune probably happens a few years ahead of Undertale which JaruJaruJ talks about also in his theory about the identity of Kris. Actually, wait a minute...Who is Kris?

Well if it is an alternate timeline who is Kris? You may think it could be Chara because of the striped shirt that they wear but characters in Deltarune can wear different clothes on different ocassions so that is not solid evidence. If we check out another JaruJaruJ's theory they explain that the only eye colour that matches Kris' is Frisk's as when they open their eyes for the first time in the series they are red like Kris'. even though Frisk was possessed when they opened their eyes, we don't have any evidence to know that when a human is possessed their eye colour changes. This abnormal eye colour could explain why Frisk and Kris seem to not be around humans as they may have faced some difficulty fitting in.

I'll probably discuss more theories in another part if you want! :D