I was talking about this one.
* Client ruler potential fix NOT RETROACTIVE
o Updated 2008-06-08: Fixed german reform marker spam.
o Due to reported problems with the optimized client ruler script, LordBula has created this package which may be both faster than the original 1.1 client ruler script and work as intended .
o NOTE: This fix includes several of the files that are affected by other fixes (and should contain their contents). Make sure that this fix is the last one you apply, so that you don't kill part of the changes this is supposed to make with the other ones.
o Download this file from the EB FTP.
o Unpack into <RTW directory>/EB/data.
o Please report whether you still get problems with interlopers and impostors where they shouldn't be!
As you see it is not retroactive so you cant use it mid campaign.

Is there any easy way other than the Rome Shell to give him the trait? Something via script? I have a great campaign and I want this to work. I would really appreciate any help.
Nope and that is the problem. There is a name collision in your game.
You would have to assassinate character that is causing problems before you can use console command to add trait to your client ruler.