Curious, if every third party got only one more unique rep (can include Konami despite Simon), who would you want it to be? You can include third parties not in yet (as well as deconfirmed characters).
Konami: Bomberman
Sega: Joker (Sorry Sonic series, but I'd like more series if I had to pick)
Capcom: Dante
Bandai Namco: Heihachi
Square Enix: Sora
Microsoft: Banjo & Kazooie
Activision: Crash
Some companies I have a lot more difficult time coming up with possibilities than others. Also, apologies if I made any glaring errors, as I'm basing it off a list I made previously doing research.
Oooh i love these ones, i'm gonna let my autism go wild:
Digital Extremes: Excalibur from Warframe
Rockstar Games: CJ from Grand Theft Auto
VALVe: Scout from Team Fortress 2
SEGA: Dr. Eggman from the Sonic games, Beat from Jet Set Radio
Activision Blizzard: Diablo from Diablo, Tracer from Overwatch
Warner Bros. Interactive Entertainment: MOTHER****ING BATMAN FROM THE BATMAN ARKHAM SERIES, Scorpion from Mortal Kombat
Traveller's Tales: a LEGO character from the LEGO games
Crytek: Prophet from Crysis (AKA the dude in the nanosuit)
Capcom: Phoenix Wright from Ace Attorney, Frank West from Dead Rising
Id Software: Doomguy from DOOM
SQUARE ENIX: Agent 47 from Hitman (AKA the Hitman guy), Lara Croft from Tomb Raider, Adam Jensen from Deus Ex
PopCap Games: Football Zombie from Plants VS Zombies
DICE: Faith from Mirror's Edge
Oddworld Inhabitants: Abe from Oddworld: Abe's Oddysee
Deep Silver: Mr. President from Saints Row IV
Devolver Digital: Sam "Serious" Stone from the Serious Sam games
Level-5: Professor Layton from Professor Layton series