Avengers: Endgame is a love letter of a blockbuster, paying tribute to the decade-plus of films that came before it in inventive and exciting ways; a true three-ring circus of Marvel mania, full of characters from every part of the MCU. Here's a breakdown of the characters with more meaning than you may have realized. Endgame sees the surprising return of the charismatic Frank Grillo as Brock Rumlow, aka Crossbones. He appears in a new scene meant to take place just moments after the conclusion of The Avengers' Battle of New York, but before the whole team clocks out to go and get shawarma. In his Endgame scene, Grillo is still a couple years away from exposing himself as a HYDRA lackey, still sporting his pretty face before the events of The Winter Soldier left him a burned-up, vengeful supervillain. While he was talked up as a main antagonist of Civil War, his fate there was mostly to be used as a hand grenade for Scarlet Witch. While he never reached his full potential in the MCU, Crossbones is a recurring nemesis for Captain America in Marvel Comics. But in the movies, he was promptly leapfrogged and sidelined in favor of bigger and better foes. Due to a number of complicated, business-related reasons, Marvel Television and Marvel's movies have never really been that closely-knit, despite technically existing under the same umbrella of the Marvel Cinematic Universe. With a few exceptions, the two worlds have been kept very separate. If you have any doubts about this, ask someone who's only watched the movies if they have any idea what an Inhuman is supposed to be. It's a situation that makes the appearance of Edwin Jarvis in Endgame all the more surprising. Edwin is the butler of Howard Stark and the sidekick to Peggy Carter. But unlike his co-lead, who was first introduced in the movies, he's never before made an appearance in the movies of the MCU. Watch the video to learn more about the characters in Endgame with more meaning than you realized!