Alright, I changed it to the following:
"Arenar has what would seem to an observer a low-level for of multiple personality disorder, though it is not a disorder given that he can switch between these two personalities basically at will."
Basically what I'm trying to say is his alter ego is different enough that it would seem to a casual observer that he has multiple personality disorder, when in fact he does not, just an alter-ego he uses to keep his other activities somewhat secret.