8. Eliminated The Shade In The Astral Plane
A whole bunch of out-of-character weirdness happened to Peter Parker during J Michael Straczynski's run on Amazing Spider-Man, culminating with the frankly inexcusable retcons of having had Gwen Stacy bunk up with Norman Osborn and sired a couple of Goblin children before he killed her, and then the One More Day fiasco nobody has the time nor inclination to go into here.
Before he got into doing real damage, however, Straczynski was just having fun taking the character in new directions, and getting used to playing in the wider Marvel Universe sandbox. One early storyline with artist John Romita Jr had the webhead teaming with Sorcerer Supreme Doctor Strange.
A new villain called The Shade had been abducting homeless youths and taking them to the astral plane for presumably nefarious purposes, you see. Endowing Spidey with some natty magic power, Strange let him deal with it.
Dealing with it apparently necessitated erasing him from existence with those magic powers. Again: no remorse. Scary.