mmmmm hmmmm it's really hard to say! 🤔 honestly, i don't think this is quite fitting, lol, because ivan (to me) does not read like he's fantasizing and delusional about the "could-have-beens" with till — he's very aware that he himself is an unloveable freak (in his own perspective) and there's nothing he can do to make till like him.

limerence (per the definition) includes this piece: the limerent person struggles to think about anything else [except] their “crush” and neglects their social life, work, and other responsibilities as a result — which is simply not ivan at all.

what ivan is to me, is an organized psychopath. he is extremely socially aware of the rules and what he can get away with. what he has to do to get away with...whatever it is he wants to get away with. in canon, it's not necessarily that he wants to commit egregious crimes towards till (quite the opposite) — he just has no impulse control and blurts out the first thing on his mind at the cost of it sounding totally fucking insane lol.

he has an unhealthy attachment, i'm not denying that at all!! but i mean, just think. he could have fought till (and won) when they ran away together to make till stay with him. but he followed till back to captivity. if he was living in this fantasy world like "our lives will be amazing together if we could just get out of here"...wouldn't he have done that? haha

if we have to pick a DSM-5 aligned diagnosis, to me, it would be an antisocial personality disorder: pervasive pattern of disregard for and violation of the rights of others, lack of empathy, lack of remorse, callousness, bloated self-image, and manipulative and impulsive behavior.

thanks for recommending the video - it was an interesting listen :3