The Marvel Cinematic Universe has expanded significantly with its latest film Eternals, including introducing the MCU's Dane Whitman into this shared cinematic universe. While Dane hasn't yet claimed his superhero destiny to become the Black Knight in the MCU, his comic book counterpart has a long, complicated history as a hero in the Marvel Universe. Among Dane's more turbulent relationships in the comics is his standing among the Avengers, alternating between a valuable ally and full-time member of the team to a nuisance and headache for Earth's Mightiest Heroes who constantly seeks to prove himself.
Created by Roy Thomas and John Buscema in 1967's Avengers #47, Dane Whitman inherited the mythical Ebony Blade from his villainous uncle Nathan Garrett who was mortally wounded in a battle against Iron Man, targeting the Armored Avenger through his best friend Happy Hogan. Passing on the cursed sword to Dane, Nathan begged his nephew to restore honor to the family's legacy and redeem the mythos of the Black Knight, and Whitman accepted. In Dane's debut as the new Black Knight, he was attacked by the Avengers, who initially mistook him for their enemy. As the Black Knight, he then infiltrated the Masters of Evil to gain information about the supervillain team's activities. Impressed by his heroics and dedication to atonement, the Avengers granted the Black Knight provisional membership on the team.
This provisional status would ultimately save the Avengers from Kang the Conqueror, who was able to gain dominion over the team and plotted their demise. As the Black Knight was not a full-time member of the Avengers at the time, Kang had no power over him, and Dane defeated the time-traveling supervillain. For saving them, Dane was awarded full membership to the Avengers, playing a prominent role in stories like "Operation Galactic Storm," but leaving at intervals when the Ebony Blade's blood curse significantly impacted his mental stability. However, it was Dane's relationship with the Eternal Sersi that would put the biggest strain on his standing with the Avengers.
To improve Sersi's mental instability, the Eternal Ikaris telepathically bonded Sersi and the Black Knight in the hopes of stabilizing her. This would ultimately do little to stall Sersi's degenerative condition, and she eventually snapped and destroyed Avengers Mansion before she and Black Knight fought against the team. Coming to their senses in the heat of battle, Dane and Sersi departed for the Ultraverse for a time and, while Dane would work with the Avengers after his eventual return, his standing with the team was never quite the same, with Thor privately regarding him as one of the most annoying heroes that he has ever worked with, and the others considering him to be a self-suffering joke.
While the Black Knight has continued to play a major role in the Marvel Universe, growing in power as his connection to the Ebony Blade has grown and appearing prominently in the crossover event King in Black, Dane Whitman still hasn't quite regained the respect he deserves.
Always searching for ways to overcome his family's dark, bloody history and prove himself worthy of standing alongside Earth's Mightiest Heroes, the Black Knight and the Avengers have one of the more complicated dynamics among the superhero team's shifting roster. And with Dane still fighting the curse that has defined his family, this relationship isn't poised to be smoothed over any time in the foreseeable future.