So frow what I read , if I play the ERE and the WRE fall then I got the "Last Roman empire" Decision , the thing is I dont have it.... I check everything , I'm ERE emperor of Roman culture.

Could this be block because I choose the 480 start date and made a custom character ?

Because rigth now I cannot use anymre the imperial reconquest CB , and at the same time I cannot reform the Imperium romanum so I'm kinda stock