excellent points size.
A personality is just that . . . a personality. A personality cult is already defined (above) and is a group rather than an individual. A charismatic personality may still be an influential leader of a group, without it necessarily being a cult . . . but you then need to assess the behaviour of the group, and analyse whether or not control mechanisms are being employed . . . Behaviour, Information, Thought and Emotional control. All of the mechanisms are employed by using the psychological influences of guilt and fear . . . the prospect of losing salvation, losing reward, condemnation, disapproval, status, abandonment, isolation etc. In religious cults the concept of a utopian reward along with the concept of sin and condemnation, are powerful influences used to channel and restrict information, behaviour, thought etc. Black and white concepts (them and us, angels and demons, holy and unholy etc) remove the room for individuality, opinion or dissent, creating a contrived sense of willingness to conform. At that point, even flaws in ideology or doctrine become indiscernable for cult members. One of the easiest ways to identify a cult . . . is to hear the experiences of ex-members LOL.
I would argue that a utopian reward, to some degree, is also presented in politics but what is different is that the police force provide a level of stability which in religion is sought (sometimes to an inordinate degree) from prospects of salvation, losing reward etc. Mind you there is still a level of conformity even in a policed secular society but even so the freedom that results is enormous.
I guess a charismatic leader would need to keep aware of how much they try to control those whom they have fellowship with by means of concepts of sin, condemnation and salvation and how much what they are saying is solely for encouragment and love.