When you are trying to get that guy to react to a trait do other guys with the name Kaeso happen to react? If so, there is a chance that the guy you want has a name like lets say KaesoF Romanvs and the guy that reacted to that name also shares the internal name KaesoF Romanvs. If there are two guys with the same internal name, the codes will only work for one of them. It seems that there is a small chance that exiting out of the game and restarting it will cause the game to change which one it recognizes. Although, most likely you will have to either not use codes on the guy that isn't recognized or kill off the other guy to get there to be only on.