The Forever King, the Forever Harlequin, Charmcaster, Hex, Doctor Animo, Clancy, Zombozo, Psyphon, Kraab and Vulkanus. I'll go through each of them to explain my reasoning.
The Forever King is obvious, the original one to have created the Negative 10. But I will showcases a bit more of an insight of the Forever Knights, and how they are split into four factions, Driscoll only being one part of it, same as Enoch.
The Forever Harlequin is my replacement idea for the Forever Ninja, as he always felt out of place. The Forever Harlequin is a mysterious, voiceless female figure who appears to be the one middle ground member of the forever knights, making sure they don't do anything too stupid. She also has a wide arrange of strange attacks and weapons, and Ben doesn't like fighting her much as her tactics are normally annoying to deal with, haha.
Charmcaster and Hex, to give more time to showcase their relationship, and the problems behind it and why they happened. I'm thinking of including a scene that has Charmcaster finally snap at her uncle, before running off to later appear in Alien Force again, while Hex finally starts to rethink the things he's doing. Perhaps Gwen even being the reason this outburst happened.
Doctor Animo, cause I'm not gonna leave out best crazy sciencetist man. And I like the idea of showing him and Clancy sort of have this weird friendship, that only they get one another, due to their connection to animals.
Zombozo instead of the circus trio, because he's supposed to be more of the major threat compared to them. I want to also keep playing into the mystery of what he is, and make him more horror-focused like in his first appearance.
Psyphon is an interesting case, but basically, I've decided to have him from the start being Vilgax's minion, so he can be a showcase of one of the many worlds Vilgax's has conquered. His presence is also going to help me explain how Vilgax got out of the null void after the team-up with Kevin, as Psyphon manages to open the null void after sneaking away into the Plumber base, and basically ditches the Negative 10 the moment he gets Vilgax out of there.
Meanwhile, Kraab was hired by Psyphon, without the others knowing, to make sure everything goes smoothly for him. Kraab pretending to be there because he hates the Tennysons (When really he doesn't care, he's just there to get a job done).
While Vulkanus is there because he hates the Tennysons after their last encounter, stuck on earth due to his ship being destoryed. I would imagine him being the one to start a lot of arguments with the Forever King, due to the Forever Knight's hateful views on aliens.
