For a spawned person for the role, yes it is possible to edit that person in "Realm of Magic". Click on the character. Choose "MC Command Center". Then "Sim Commands", then "Modify in CAS".
(Do not click on the first "Modify Household in CAS" or they become a played character and a new one may be spawned to replace them)
Without MCCC, there are a whole bunch of cheat codes you can put in. Basically the "mod" already has those codes set up in a menu.
As for assigning one of your own? I'm not sure on that. My guess is probably not for one of the main magic gurus.
