There is a bunch of good information in the thread if you haven't read through it.
Eiji is a cheap bastard. You gotta understand is move list to stand a chance. His qcf+C has hella far reach and can even stop hops pre-preemptively. His dp+P can reflect fireballs and has a big hit box. The heavy punch version is active FOREVER which can throw people off. His hcb+D slash is safe on block, and his qcb+P is a good anti-air. He has many good tools for many different situations. his qcf~hcb+P super has an enormous hit box and it's good as a whiff punish, anti-air and to snuff out fireballs.
For your characters, I would avoid throwing fireballs at Eiji if you're opponent is good with his dp+P reflector and when he has meter, his fireball super as I mentioned can eat them up.
I would also say you should try your best to get close to him as you can and pressure him. He doesn't have an invincible reversal, so if you knock him down, stay on his ass.