The Black Knight is involved heavily in Endgame! and it is the second part of a series where the Avengers failed the first time as they went up against Squadron Sinister.
It looks like Marvel Comics may have just revealed where the title for Avengers: Endgame came from.
Even if the Black Knight doesn’t show up in Avengers: Endgame, Carol Danvers could be taking that spot in a change from the source material.
The Black Knight was able to defeat Kang and then the Grandmaster revived all of the Avengers.