I was living with my roommate last year, and I have since moved out.   He and I both played on Nostalrius.  He 100% knows my email that I used for creating my original account on Nostalrius.  I'm very certain (not 100% though) that he knows my account name, given that it was visible on my computer often.  He also had access to my password, as I allowed him to log on to create reagents/transmutes on one of my characters. 
  
I was able to use my old Nost e-mail to generate the token on an Elysium account with a new email (i was told by friends and read on the server that changing email addresses was suggested by the staff).  However, I no longer have access to my old nostalrius e-mail.  I used the same password for that email as my log in account password, so I believe he may have used that information to change my Nost-email password.   The guy hasn't responded to my messages.  I'm a little worried he may be trying to steal my characters.  
Can he take my transferred characters back using the Nost Email + Nost Account name and password????? 
  
Also I'm not sure if he has pictures of my UI or not, but those were posted onto our IRC chat and guild forums pretty regularly... Should I be worried if he shares pictures of my characters' UI to an admin?  Should I pre-emptively send my own pictures to the UI?