I'd cleaned out the Boil long before I could talk to Willoughsby or Sebastian, but got Sebastian to join the group. I've been having him churn out his unique products (useful for my master thrower PC) and stock piling them and otherwise acting rather inconveniently paranoid that he's going to up and leave for some reason. For example, my alignment is usually pegged at 100 to the good while his seems to stay at 2. My charisma's at 20, but that's an augmented green with the help of I forget what, so I'm not sure if the charisma bonus is actually in effect (e.g. Swyft still took off as soon as we reached Tarant, not that I cared).
i have that same charisma bonus, and i've killed enough good guys for gar to leave, but he hasn't... even when it's a green twenty, it works...
As long as you have charisma of 20, even if part of it comes from the gypsy blessing or the ring of influence, the follower NPCs you recruit will not leave. Similarly, if you are a persuasion master, you can convince the holier-than-thous to join evil incarnate and vice versa. Swyft was different because she was a QUEST follower. Same for Arronax, Tollo, and Dante (pretty sure anyways). They do not count against your limit but are only on board until the completion of a certain quest or reaching a certain place. Having the charisma bonus does nothing to those kinds. However, as Sebastian is not one of those, even though you usually have to quest to get him, he will never leave based on anything you do unless you ask him to. Worry not...
i'm gonna agree with 3dogs... swyft seemed to count against my limit... after all, her pic was on the side of the screen with the rest of my followers...
I don't know about Dante, but Swyft, the Doc of Shrouded Hills, dog, and Arronax don't count even though they temporarily join your list to tthe left. I think this is the game mechanics way to add their kills to your Exp bank.
NPC like swyft do not count against your followers. I had a chrisma of 8 and 2 NPC's. I thne picked up swyft and went to tarrant. I had 3 with her and I only had a chisma of 8, so quest followers do not count against your limit.
I am absolutely sure that these NPCs do not count against your follower limit: Doc Roberts, until the bank robbers have all been killed; Dog, a permanent freeby; Swyft, until you reach Tarant; Lady Druella, until you kill Sir Garrick; Cynthia Bogg, until you've escaped the Isle of Despair or brought her to the women's camp; Arronax, until the endgame; and Tollo Underhill, until you escape the Pits (by the way, if anyone wants him as a free follower, go down to the pits, tell him you're here from K'an Hua to rescue him [even if you're not], and that you don't have a plan for getting out. He will suggest escaping through some tunnels or what not. If you do that, then he leaves as soon as you're out. But, if you use a scroll of exiting [possibly also teleportation], he won't leave after you've got out of the pits. However, he is still counted against your max limit, if you ask someone to wait or something. Decide for yourself if he's worth that much trouble). Sometimes, for one reason or another, Dante or Chukka will join my party even if they would be over the limit. I cannot account for that. Also, Gar will join you if you free him even if it puts you over the limit. However, he counts against the limit, and as soon as you ask someone to wait, well... Those are the ones I am positive about. If at any point someone finds otherwise (excepting Dante or Chukka), let me know.