I have an idea for a fan-made Eva RPG (and yes, I know about Adeptus Evangelion). It would use the Storytelling System (specifically, the version in the God-Machine Rules Update). The Integrity/Humanity/whatever scale would be Stability, the Blood Potency/whatever scale would be Synch Rate. There would be three types of Pilots:
Normals (think Shinji): bonus to Wits or Dexterity
Trained (think Asuka): bonus to Presence or Strength
Clones (think Rei or Kaworu): bonus to Resolve or Composure.