There's a lotta cool psychology going on with Cult Leaders
Like people above have stated, they don't prey on the healthiest of individuals (exactly like gangs they go after vulnerable people). They have a firm belief, or at least can fake it to an extreme degree, that they are the next incarnation of whatever god/jesus/apostle/saint/prophet/whatever they talk about
Another of the big things that go on within Cult Leaders (if I'm interpreting the question correctly it's about the leaders themselves rather than the people who join?) is that they're CONTROL FREAKS TO THE MAX.
They have a strong desire to dominate and control. And I don't mean their own lives or the people around them. They're megalomaniacs who want to control as much of the world as possible. And when people start blowing smoke up your ass all day everyday, you see these suckers surrounding you that'll buy anything you say. You start to let it go to your head and it ends up becoming similar to rich empire builders who are chasing the next big high (although in this case instead of money it's more about what you can get away with doing)
Nothing's ever enough for them.
After you've convinced 100+ people that you're God what's after that? Because it'll be interesting for a little while but then it'll get boring. Imagine a bunch of drones around you all day that will literally say yes to anything you say. You could say the sky is green and they'll be like "thank fuck you told me because sure as shit it is!"
And eventually the leaders themselves are going to want to push it because they get off on that kind of control. After a while it just kinda spirals further and further though.
Then finally you reach a point where you start to believe your own bullshit and start thinking "wait, I AM God so why am I following such dumb things as laws? I shouldn't have to follow laws, these dumb shmucks need to follow MY laws"
Because these people started out with a strong need to spread their own will and ego. Then when it starts to work these people are just going to let it go rampant because they were never the type to slow themselves down or even be cautious. They love the rush of doing whatever they want, but then whatever they wanted starts to get boring and so they start to want the next thing.
You start off with saying the sky will be green on Fridays and then you' implementing rules about how you get to fuck everything that moves because it's good cleansing for their souls or whatever.
________
And if you're struggling to empathize with them, then think about these things:
1) video games. Do you still play the same games you did as a kid? And I don't mean party games that you can play with other people, I mean games you play by yourself. How often do you revisit them? If it's every once in a while that's not what I mean. I mean you beat the game, got 100% finish clear on everything and then you delete your account the next day to start over. Do you ever do that?
How often do you start a new account knowing every last secret of the game as if you'd designed it yourself after playing 500 times?
If you're like most people, that sounds boring to you. After you've played through something even 5 times it's going to be boring. You're going to want to do something else. You're going to want to play the next game
You want to watch a new movie, you want to read a new book, you want to go to a new venue. If you go/do somewhere/something enough times to the point where you could literally set your watch to what's going to happen it will get boring.
For a great example of this watch the movie "Groundhog Day". Guy is forced to go through the same exact day for decades. There are fun little moments for him but ultimately he's miserable. And most of us would be too, we want something new
2) Do you like dominating women in bed? That's similar to what Cult Leaders want, the only difference is to the degree. You may just want a woman or two whereas these people want hundreds. The drive is the exact same. The feelings are the exact same. It's just to the level or degree that you want them or want them extended to
One year you're happy in missionary simply losing your virginity and then a few years later you're asking women if they like to be your personal slut while fucking her from behind. Shit happens >.>
For a less extreme version of number two, how often do you repeat the same positions in the same order with the same amount of time and in the same place with the same girl? Don't get me wrong, we all have our tendencies and our favorites, but you're not setting your watch to it every time like "Okay, that's missionary first position for two minutes which means I need to flip her over to doggy now for the next three minutes and 22 seconds and then she'll cum. Then I can get her on top of me for 20 seconds so I can finish"
It just doesn't happen. We'd be miserable after a little while of that. Even if it was the hottest chick in the world to you *cough Jennifer Lawrence*
