Title card's issue homage: Fantastic Four #109.
When the comic book character Nebula made her first appearance in "The Avengers" #257 (July 1985), she claimed to be the granddaughter of Thanos, who at that time was believed to be deceased. When he returned some time later, Thanos denied any family connection. Later incarnations have presented her as one of Thanos' adopted daughters, but this version inexplicably presents her as his older sister.