This is extremely well written. A good mixture of body horror, regular horror and lewd.
I noticed a couple of minor spelling issues, but the only thing that stuck out to me was that you have a portion of Rocky's speech in his Thrall Ending colored as Jarby's speech.
I puzzled out all 12 endings. My favorite is probably Dillon's Thrall Ending. It's... comfy, if a little melancholy. The 'best' ending IMO is Dillon's Freedom Ending. It feels like it has the strongest setup for 'doing something about it'.
Spoilers below:
I appreciate the inclusion of things that grey the water on freeing people. Andrew preferring the hypnosis to his old life is a good touch, and Rocky being completely broken without it is an interesting (and horrifying) wrinkle. I like the plot detail that the more hypnotized a thrall is, the dumber they are. It's a well thought out drawback to vampire thralldom.
I love Andrew and Jarby's relationship. I love that, despite Jarby clearly holding all of the power, Andrew can boss him around like the Big Bro he's hypnotized to be like.
I love all of the characters. Except Throckmorton, he can jump off a bridge (I'll help). Everyone has an interesting bit of nuance to them, and with all the enthralled folks, the little peek at who they were before they were enthralled is very interesting. Lots of unanswered questions that are interesting to ponder.
IF you were to ever return to this project (I read that you at some point just had to call it done. I know what that's like) I would personally like to be able to get more lewd with everyone. It's possible my particular path veered away from some of that stuff, but the scene where you just ram your face into Andrew's armpit was 👌👀💦 and I was hoping for more like it. It does sort of undercut the frantic nature of your attempt to escape, but there are some hints that the MC is kind of horny about his predicament even if he's also horrified by it (and horny horror is my favorite kind of horny). Dillon's huge cock comes to mind...
And there feels like a huge lack of overt interaction with Jarby himself. I was hoping that waiting with any of the NPCs would allow an interaction with Jarby, even if it's just a few words of terse conversation before he knocks you out. Maybe just an option to suck his dick while he's sleeping, or bury his face in your armpit (to smother him??? He probably doesn't need to breathe.). Jarby is heccin cute, even if he's a goddamn monster.
Anyway, thanks for coming to my ted talk. Sorry for posting a wall of text, but I really enjoyed this. It's got me thinking about how things could go. How one might achieve something resembling a good ending. (Get a steel mirror and force Jarby to hypnotize himself into not taking any more thralls and freeing you, Dillon, and your beau? Would killing him break the hypnosis for everyone? Could you become a more powerful vampire and take control of Jarby's situation?)
So, uh, good work uwu. Keep it up!