Dark Magician Beth will undergo a Heel–Face Turn at some point.
Her Hero description mentions that the Knight thwarting her plans has caused her to doubt the teachings of an as of now unknown "Savior", implied to be the leader of the Invaders so maybe she'll either join the side of good after either seeing her own side do something even SHE couldn't condone, or see what she was actually fighting against and try to repent.- Potentially Jossed: She got presumably killed in World 11-6's boss fight, although since you go back in time soon after it's likely she's still around in the present time.
- She shows up in World 12, and has been reduced to a despairing drunkard. Not quite a Heel–Face Turn, but it does leave credence towards one potentially happening.
- She agrees to help you in World 13, but this is due to an Enemy Mine situation involving terrorists. It's still a step in the right direction, as she was helping out other, in her own words, 'contaminated' out of her own free will before meeting back up with you.
- Potentially Jossed: She got presumably killed in World 11-6's boss fight, although since you go back in time soon after it's likely she's still around in the present time.
Both the Knight and the Little Princess aren't entirely human.
The Folktale side story gave us a cutscene where the Grim Reaper becomes shocked at the improbability of the Knight's survivability throughout the story and questions what they really are. World 11 and subsequent events connected to the Unrecorded World gave us a cutscene where the former Kanterburian queen Lili asks current queen Camilla if she ever had a little sister, and also the fact that the Knight and the Princess have always been connected to each other ever since they were kids. This leads me to believe that there is more to them both than meets the eye, and that Season 2 will delve on their true identities and purpose in the prophecy. The Little Princess' name is Princess.
The reason why her name never gets mentioned is because we already know it. Big Jack and the evil fairy will end up becoming Champions later on in the story.
We already know that Kaden and what may potentially be Heavenhold itself will be Champions given a few hints in the game, but we still don't know who the big one and the fairy-like one are supposed to be. Currently, the ones that can fill the spots are Big Jack and the fairy from World 6.- Unlikely. The Champion Sword has always reacted when encountering one of the Champions for the first time, which specifically did not happen when you first meet either of them.
The reason why Sohee and Fei/Mei aren't part of the Champions that got mind controlled by Camilla is because they're associated with the Light element.
Let's break down the four Champions that are under Invader!Camilla's control: Coco (Water), Marvin, Marianne, and Craig (all Earth). Sohee (jailed in Demonshire) and Fei/Mei (used as bio-batteries for the AMMI), who are of the Light element, seemingly avoided Camilla's clutches. There's also the fact that Aisha, who is also associated with Light, was nowhere to be found in that cutscene and is still M.I.A, which could mean a few things: a) Camilla couldn't mind control her and escaped, b) she's still somewhere in the Demon World, or c) she wasn't even there when Heavenhold fell and is still in the Rah Empire all this time. Could there be something about having the Light element that impedes with the Invaders'mind control technology?