Responses
I didn't read the novel, but based on the webtoon's context, Sylhan is a high priority prisoner. Fjord is the king of another nation. He can't just steal Sylhan away, that will start a war. If Lister knew Fjord was actively in contact with Sylhan, he'd lock him up, or worse. Likewise, we don't know how much Fjord knows about Sylhan's current situation since he's been away at war for 2+ years.

I still think ML fishy. And I totally agree with all complaints about him. “He is busy with making MC king again that is why he can’t help”. Fucking priorities? Not letting your lover be beaten, mutilated, raped>>>>>>making him a king. So what is really fishy is the fact ML really is good at spying with magic, it really hard to believe he doesn’t know what Lister did to him systematically, but if he did known and done nothing . No wonder some people had impression it will be a “ML actually only uses MC, but later he actually falls in love”. And as story goes things are not getting better.