Wouldn't put someone like Ted Bundy in the same category as charismatic people, as he was psychologically defunct and delusional. It's the same as saying a psychopathic leader is charismatic, I'm looking at you, Manson (or if you wan't a modern version, Copeland). These kind of people do not take you into account, only their own delusions and agendas.
Genuineness and vulnerability are 2 important criteria to consider. But I get your point, the darker side of Charisma. These 2 factors counter that.
I am still not sure that charisma can be interpreted only through “positive” examples. But that aside, my remark was not towards the dark side of charisma, as much as I wanted to suggest that, like often in a scientific research and particularly one with a variety of cases to compare, it is that which is atypical (uncommon) that can hint to deeper understanding.
Though there are better examples perhaps, I’ve brought up Bundy’s "supposed" charisma (as accounted by his biographers and stories of his personal relationships with females), because it could exemplify the relevance of the relational context for the topic – in a way that to understand charisma, we might need to reflect not only about what one person is or has, but about people who perceive as well.
Adding to the qualities listed by other forum members in the previous posts, in my view charisma strongly relates to sense of self-awareness and self-acceptance reflected in the physical presence, mannerism and body language (something that Ren mentions in his video as a calming presence of an INFJ). It also has lots to do with being driven by a sense of purpose or the highly significant personal goal (noble or not), but most of all, I would say it is about communication or "storytelling" skills (including and beyond rhetoric) – which result in projecting a particular narrative of relatability and emotions that resonate with the observer/recipient at an emotional level at which they themselves are particularly susceptible (or vulnerable). I’d even dare say that such skills do not have to be necessarily inherent to person, but one can work on them.
Perhaps I am too influenced by current research and readings on lived experience, but I also believe that to speak of a charismatic person, one has to experience their presence (in some way); otherwise, how can we be sure we are not only speaking of one person’s impression of another person?
I am not psychologist to provide foundations in theoretical insights, anyway; these are only my personal observations.