I would remove the following teams: Mexico, Another World, Villains, South America and DLC characters Oswald & Najd.
My new/returning characters would be:
Nest: Krizalid, Angel, Nameless
Anti-Kyokugenryu Team: Eiji Kisaragi, John Crawley, Mr. Big
Garou: Kain R. Heinlein, Grant, Rock Howard
New Teem: 3 all New Characters
As I added Rock Howard (formly DLC ch) I would pick the 3 following as new DLC: Wolfgang Krauser (FF), Rugal & Adelheid Bernstein.