Basically after seeing all these "forgotten" character threads I noticed they all have 1 thing in common most to all of the characters they list are 3rd party.
With that said post a first party character that is either forgotten, unknown or you feel hasn't been given a lot of representation in the past few years. (only third party characters I'd accept for this thread, are ones whose series was once published by sony.)
Eiji Shinjo (Battle Arena Tonshinden)
Why? Battle Arena Toshinden, was the first fighting game solely published by SCEA (Tekken was co-published) and one of the first games on the PS1 to utilize 3-D fighting. Eiji was the central protagonists of the game making him the best choice to represent his series.
The last thing this game needs is another guy with a sword.
They could use a magic user of some sort though... like Ghaleon from the Lunar series:
Or Vivi from Final Fantasy IX
Or Oliver from Ni No Kuni (coming out this January)
Jeanne-Jeanne D' Arc
Ari and Stan-Okage: Shadow King
Jaster Rogue- Rogue Galaxy
Max and Monica-Dark Cloud 2/ Dark Chronicle
Leonard-White Knight Chronicles