Unmarked spoilers ahead!
The OMORI Mod
Daphne will appear in the mod's waking segments as a major character.
Considering that her Headspace counterpart is in the main party and based on an in-universe real person, and Sunny is starting to explore new people and experiences...- That seems extremely unlikely, given that Daphne and her family were last seen living in Faraway Town, and this mod takes place after the ending of the game where Sunny moves out of said town.
- People Sunny met before could visit him sometime, though. Heard that their brother Mikhael said he'd be going somewhere else as well.
Space Fangirl is Faraway Aubrey dreaming herself into Sunny's new headspace.
Her overworld dialogue sprites have a similar V-shaped smile, rounded chin, and facial expressions to those of the old Headspace Aubrey. Both also have strong domain over Happy and Angry emotions as well.Aubrey even enjoys Space Boyfriend comics, even having a poster of him in her bedroom. His appearance on a comic book's front covernote has the same headgear, and same cape and shirt colors; as Space Fangirl's cosplay as well.
Other major bosses such as Jawsum and The Slime Girls will assist Sunny in future chapters.
We already have 3 major bosses in our party and Sunny hasn't really made enemies with any of the returning bosses such as Life Jam Guy and Kite Kid so far.