@MrMcNasty
If he had a personality disorder, he wouldn't be able to 7 time.
The issue is that that's not really true, as having a personality disorder does not necessarily mean you have a lower intelligence or charisma.
It's unknown how long he was dating seven people at once for, and it is true people with ASPD tend to suffer from an inability to maintain relationships, however, psychopaths/sociopaths (which are put under the label of ASPD) are known for their superficial charm and charisma.
They're also known for their infidelity as well, however, so it's not too unlikely that he could have been in relationship for some time with at least some of them before he let the cat out of the bag, as some high functioning psychopaths or sociopaths are able to remain undetected for years.
He just has no sense of shame nor guilt.
From the NHS's website:
A person with antisocial personality disorder may:
-exploit, manipulate or violate the rights of others
-lack concern, regret or remorse about other people's distress
-behave irresponsibly and show disregard for normal social behaviour
-have difficulty sustaining long-term relationships
-be unable to control their anger
-lack guilt, or not learn from their mistakes
-blame others for problems in their lives
-repeatedly break the law
-He exploits/manipulates Sayu by having her have sex with him as she's a runaway
-We both conceded and characters repeatedly state he lacks regret or remorse
-He repeatedly does not seem to understand what normal behavior is or how people act in certain circumstances, and cheating with seven people, having sex with a minor, and even just how awkward and unable to read emotions he is demonstrate it
-He has demonstrated that after his 7 girlfriends left him, he lost all his friends and connections, and was unable to feel attached to anyone, and so felt very alone because of it.
-We haven't seen his anger, but I believe it was implied that he gets nasty when he gets angry. Even if he doesn't, there is
high functioning psychopaths/socipaths are able to actively hide or mask their anger under the sense of normality
-He doesn't necessarily blame others but he also doesn't take responsibility. He seems to think that the seven girls left him for reasons beyond his control as he describes it as something that just happened, and doesn't seem to understand why Sayu left him, because he seems incredibly happy to see her again.
-Again, sleeping with a minor for a quid pro quo situation, and wanting to do so again.
A diagnosis can only be made if the person is aged 18 years or older and at least 3 of the following criteria apply:
1. repeatedly breaking the law
2. repeatedly being deceitful
3. being impulsive or incapable of planning ahead
4. being irritable and aggressive
5. having a reckless disregard for their safety or the safety of others
6. being consistently irresponsible
7. lack of remorse
Of these, he undoubtedly falls into 3, 5, 6, and 7, could arguably fall into 2 and 1 and only dos not fall into 4 based on what we've seen.
I think it's pretty clear what's going on here.
He's attracted to Sayu specifically because she didn't like having sex with him. He wants that feeling of dominance again
That's undeniably an element, though he never admits that its specifically the dominance he wants, just that he wants to see her again. (Though, if he wanted dominance, I suppose it could be seen as him trying to have control over something, anything, in his life that seems to be falling apart.)
However, it's clearly not the only reason he does what he does. In chapter 18, he describes that he's lonely and wants to have someone at his side. He wants that "emotional wetness" as he says earlier in the chapter. He's not a malicious entity, he's just unaware of how his actions harm others and why what he's doing is wrong.
I think he's a tragic character more than a pure evil and vile person. I think that if had received the proper support group or network of people who cared about him and a received professional help, he probably could work past his disorder.
It's such as shame, really.