Avengers #315 1990

Avengers #315, published March 1990, sees Captain America, Thor, Sersi, Jarvis, and guest-star Spider-Man facing a universe-ending threat. Reality has seemingly vanished, leaving only our heroes and Nebula, who is attempting to create a new universe with a powerful compressor. The team must confront Nebula and deactivate her device to restore existence. This issue is notable for its cosmic stakes and subtly initiates a retcon concerning Nebula's identity, later revealed to be Princess Ravonna, making it a key issue for character continuity.