I mean, I guess people exist who become sexually aroused by fighting strong opponents (who are twelve years old), but do we really want to be normalizing that behavior? (What do you know, I managed to tell you the context.)
More importantly, who is the target audience? Hunter x Hunterfeels like a cute kids’ show with a tad too much emphasis on fighting for the most part, but then you get stuff like this. What are kids supposed to learn? That it is cool to have some older guy obsessed with you to the point of wanting to get off on hurting you? Or are adults supposed to learn a more sinister lesson?
Aw, look at the cutesy way Gon and Killua imitate Hisoka in the “Hunterpedia” portion of the episode! There’s nothing disturbing about this at all. :P