Larry Koopaling
Cruel, composed and bland
I'd rather treat the old villains like Bowser, Bowser Jr., the Koopalings, heck even Wario in a new interesting way - like they did in Bowsr's Fury. The Broodals from Odyssey were brand new and fit perfectly within the narrative of the game, but did not really add anything new to the plot or to the game - they could have simply been Bowser Jr./Koopalings/Boom Boom/Kamek's fights and little would have changed.
Because of what I stated above, and because I really like the Mario cast as a whole, I'd use the regular cast in a new Paper Mario as the main characters, like in Color Splash, but with a mixed up storyline, like in Origami King. New characters would of course be included, but as companions/citizens/minor villains, and each one with their own personal agenda. I believe Super Paper Mario nailed the inclusion of new characters very well.
Because of what I stated above, and because I really like the Mario cast as a whole, I'd use the regular cast in a new Paper Mario as the main characters, like in Color Splash, but with a mixed up storyline, like in Origami King. New characters would of course be included, but as companions/citizens/minor villains, and each one with their own personal agenda. I believe Super Paper Mario nailed the inclusion of new characters very well.