JoJo's Bizarre Adventure/Fridge

Fridge Brilliance

 * At first, I thought that the first part of JoJo's Bizarre Adventure featuring Dio recruiting Jack the Ripper and vampirizing him was just a way to further amplify the magnitude of Dio's evil. Namely, he got the one of the scariest people in real-life England to join his side. Only much later did I realize what Araki was playing with. The battle between Jonathan and Jack ends with Jack being disintegrated by hamon force. This doesn't just explain why Jack the Ripper's killings ended without an arrest. It's also, in Jojoverse, why Jack was never identified with anyone's birth name. How do you identify someone who now only exists as a fine film of dust?
 * In Part 1, Dio had the power to even freeze blood to slow his opponents -such as Jonathan- down in combat. Why didn't he use it against Jotaro? Not his body, so he couldn't do it.
 * In Part 4, no one in Team Buccielatti comes with a reasonable explanation to Coco Jumbo's apparent resistance to The Grateful Dead's aging mist. There is actually a simple one: since lowering your body temperature even by a little greatly slows the effect down, then a cold-blooded animal like a turtle is probably nearly immune to it if not exposed to intense heat.

Fridge Horror

 * The Steel Ball Run arc of JoJo's Bizarre Adventure combines this with Religious Horror, when it becomes apparent that the cross-country race used to frame the story is just a cover for President Valentine's agenda of collecting the scattered corpse of Jesus. When he succeeds in gathering all the parts into one vessel, Valentine's powers evolve and create an effect which draws good fortune toward him and casts misfortune away. When Johnny Joestar tries to shoot him, this effect protects Valentine, but the misfortune has to be re-directed elsewhere, resulting in children being killed on the other side of the world. Given the source of this power, it casts dark, dark questions on the miracles in the New Testament.
 * On the Vento Aureo arc: remember how the poor janitor died? Now remember that the whole point of that lighter test (not to mention the whole point of making it so easy for the prospect to hide their "failure") is to awaken the prospect's Stand. However, if you don't have a strong enough psyche when stabbed (like the janitor), you die. Now consider that there's probably a relatively good-size stream of would-be entrants to Passione (as would-be mafiosi numbers go, anyway), and that the probability of each one being able to handle the strain of a Stand isn't especially high. Black Sabbath's body count up to meeting Giorno suddenly looks alarmingly high... And why should Polpo care? Each dead failure is one less potential tattle-tale against Passione...