I think mind control is one of the scariest plot stuff ever. I mean who wouldn't be terrified of it. We see hatter use it in alice also Ivy with men (and catwoman! Cuz she had a crush!) But how the other rogues would use it on people they have crushes? Maybe Johnathan ( guy got creepy with becky) Edward and harvey? I mean sorry if it is too much of an ask. It's like horror movies. It IS scary. But also curious.
BRO THIS IS SUCH A GOOD ASK!!!! It's not too much of an ask at all dear. HNNNNNNNNNG. As for being terrified of it, it does elicit an emotion in me, it's just not fear 👀💦💦💦.
TW: Mind control
Scarecrow: Jon uses chemical influence 100%. If he can make a fear toxin it's not totally beyond him to make a mind control gas. He gets a great rush from it.
It's the only way he can stop being so lonely. While under its influence he can study them all day long, both medically and romantically. Jon could stare at them for hours while they're being so "cooperative"
Jon would be "Romantic" with it. I don't mean in that sense, I mean he'd dance with them, have a romantic dinner and try and do couples things with them. Library dates, Bank robberies, Ace Lab's chemical heists. The works.
Sometimes he even forgets they're under his control until something reminds him that they're only doing what he says. It's not a permanent solution, it's just until he stops feeling lonely.
Two-Face: HYPNO COIN. HYPNO COIN. HYPNO COIN. Either he puts it on a string and uses it as a classic swinging pocket watch or he uses a more modern Hypno coin trick. (Harvey learned a lot when the doctors tried to use the same technique on him) Harvey would definitely hypnotise them into being his secretary to keep them close by. He'd be so torn about it because he genuinely cares for them and their well being but also they'd leave him if they had the chance. They make him so happy and he can't lose his only piece of happiness.
Riddler: Ed definitely uses a Hypno helmet or some kind of mind control chip. Who better to pilot someone's mind than the most brilliant mind in all of Gotham?
I'd say for Ed the appeal of having a doting mind-controlled partner gets boring to him very, very quickly. It was maybe good for the first week but when he realises he can't have any meaningful intelligent conversation with a lifeless doll he unplugs the device and drops them off at an undisclosed location. That is if he cares enough about them. If he doesn't I could easily see him killing them once they become annoying.
That being said I can see him using it on people he doesn't care about to make them help with his schemes or clean the lair for him.
Bonus:
Music Meister: Dennis took 'The Phantom of the Opera' a little too seriously. He genuinely doesn't see the nuance that the Phantom was a bad person. In his eyes, it's all for the romance. He knows what's best for both of them. When he sings and his crush is in love with him he sees them as a partner in crime. The Lovett to his Todd. The Veronica to his JD. He probably keeps them in a basement and uses his hypnosis to condition them into a relationship so they'll still be with him even when he isn't singing. It's a long, laborious process but after all, that's what love is, isn't it?
