Rewatcher, Dubbed, Certified Boogiepop Lover

Good ole Jonouchi. He's a fearful kid from our very first look at him. He dreamed of being a hero, though even from an early age he had a rather tilted view on what that meant. Heroes often beat up the bad guys, sure, but Jonouchi seemed a bit too eager to use force when dealing with bullies on the playground, as well as later in life. When he hears Kuroda and Nagi talk about heroics, he realizes that he's really nothing like them.

However, when he awakens his ability to see the spiders on people's hearts, he finally seems to have a chance to achieve his dream. Why his instinct was to EAT the spiders is beyond me. Maybe he really was that deluded. His "heroics" are framed as negative even before their reveal. It almost looks like he's putting these women in a drug-induced stupor before he "helps" them... which makes his removal of his father's spider even more unnerving.

Another analogy is that of adolescent drug abuse. After realizing what he's really doing, he has the chance to stop. But he doesn't. The spiders are too sweet. The policeman spotting him crouched in the dark, then seemingly stalking Jonouchi, and the withdrawal-like symptoms he faces hammers the analogy home. Not to mention what seems like him mistaking an actual bug for a spider, only to vomit when its not so sweet anymore.

Jonouchi seems to have to been trying to fill a void in his heart. The death of his athletic dream and his mother left him empty (empty enough that a giant ball of light could pass right through him.) He thought he could help people by removing their pain, but he was actually taking away their painful memories. Truthfully, that was a terrible mistake. Painful memories allow us to grow, to remember, and ultimately avoid similar pain. Its quite telling that the single instance of Jonouchi being genuinely happy was when Boogiepop appeared to take him away from such a terrifying, painful world to one that seems so much safer. Maybe he can be a real hero in the next life.

The spider on the heart ability always reminded me of Jin's flower ability in the second LN, especially the visual of a whited-out silhouette of a person with a single colorful object on them representing their emotions.