The Marvel Cinematic Universe is arguably the biggest film franchise of all time, and the powers that be at Marvel Studios arent showing any signs of slowing down. Theyve already got a mammoth movie slate mapped out until the end of Phase 3 in 2020, with new heroes confirmed to appear including Black Panther, Doctor Strange, Captain Marvel, The Inhumans and Spider-Man himself. However, Marvel will need a big supply of fresh blood on standby to keep audiences interested when Phase 4 comes around after all that. By then we will have seen Marvel Studios fist female-fronted superhero film (Captain Marvel), their first black title character (Black Panther) and plenty more mammoth crossovers in the shape of Captain America: Civil War, Infinity War Parts I and II and Thor: Ragnarok, now confirmed to include Mark Ruffalos Hulk. From there, Marvels sprawling interconnected comic book movie saga will need to keep things fresh and innovative if they want to keep audiences engaged and willing to delve into their wallets even more times. Certain Avengers contracts will be running thin, and theres a danger of sequel fatigue if all they did was churn out follow-ups to previous adventures. Thankfully, there are some excellent characters waiting in the Marvel Comics back catalogue. Here are the ones that could make it into Phase 4, and who should play them
