Haru noted it, when the Anti-Nightmare got caught mind-controlling people and locked up.  He wound up hosting an Eventualities comment war about psychic espers, and moderating it was a - ha - nightmare.  And then he kind of forgot about it.  It happened across the planet, it was not more than mildly interesting that there was such a full confession, Haru's got his own entire life.

Time wears on, and Haru randomly looks up what they're doing with the guy.  Probably they'll have assigned him some kind of handler so they can tote him to and from dungeons, his power's really useful and really rare -

No, looks like Kang Jaeha's still locked up.  No sightings from even the most eagle-eyed insane Korean fans.  No Korean guild lists him as a member.  Some of the parasocial maniacs are protesting his innocence, asserting that the whole thing's a frame job and Kang Jaeha-oppa is falling on his sword to protect his one true love, any of these several potential candidates.  While that's pretty obvious nonsense, they're at least strident and consistent about protesting the fact that Kang Jaeha continues to be in jail, and Haru credits that they would probably have noticed if instead he were quietly relocated to Thailand to be deployed there instead.

They have not and are not obviously going to assign him some kind of handler.  The Anti-Nightmare is apparently supposed to rot in jail forever.

This cannot be the mind-control-minimizing approach to the situation.

Haru opens up a Korean course on Duolingo and starts making phone calls.