10 Big Changes The MCU Could Introduce In Phase 4

10. The Old Guard Is Ushered Out

Iconic superheroes Iron Man, Captain America, Thor and the Hulk are the pillars of the Marvel Cinematic Universe, but their time within it might be coming to an end. Who survives the events of Infinity War and its untitled sequel remains to be seen, though that will be irrelevant if the actors behind these characters decline contract renewals.

Robert Downey Jr, Chris Evans and Chris Hemsworth's deals expire after Avengers 4, and whether they will be entering new ones is up in the air right now.

There's every chance these stars will take this opportunity to bid their characters farewell and pursue other projects, while Marvel may also wish to usher them out so it can bring a new generation of heroes to the spotlight in Phase 4 and beyond.

From a storytelling standpoint, some could be killed off while others disappear into the sunset. Another possibility is phasing them into the background. Tony Stark, for instance, could become a Nick Fury-type figure who makes cameos going forward.

With Infinity War casualties a certainty and contract situations uncertain, there's a real possibility the Avengers founders will retire after Phase 3 has wrapped up.