I hated Final Frontier. They never explain Syboks powers. How he got them or what not. Why people should just follow him when all he did was wave his hands and do a bunch of magic tricks.
He's a Vulcan. Vulcans can cloud minds. Spock did it at least twice in TOS. Sybok clearly took an advanced course, but it's apparently the same basic ability.
Why he thought "God" or whatever resided in that space cloud thingy without any explaination. Why he wanted to go there in the first place wasn't answered either.
Presumably God contacted Sybok, or Sybok contacted God.
All that I could forgive. I could not forgive them for making Uhura, Chekov, Sulu, and McCoy turn against their leader and Captain of up to 30 years. If they were all under some sort of mind control, it wouldn't have bothered me. That's forgiveable and understandable. But they were shown as being fully capable of making their own decisions. Because apparently Sybok is just so awesome no one can say no to him. Why all those fucking traitors weren't put on trail for treason, sedition, and mutiny afterwords blows my mind. It ruined TOS cast for me. It's no wonder why TUC acted like it never happened.
I'm pretty sure they were mind-controlled. Chekov might as well have been tried for treason after Star Trek II by that metric.