After stopping the Harbinger with the Weapon, Master Chief is isekai-ed to the MCU. Having another super soldier around, Nick Fury recruits Master Chief in the Avengers Initiative and replaces Hawkeye because nothing is more important than family.
How does he fare in each?
Scenario 1: The Avengers
Scenario 2: Avengers: Age of Ultron
Scenario 3: Captain America: Civil War
Scenario 4: Avengers: Infinity War
Scenario 5: Avengers: Endgame
He has access to all of his UNSC, Covenant, Forerunner weapons (two for dual-wielding weapons), equipment, and armor abilities.
How does he fare in each?
Scenario 1: The Avengers
Scenario 2: Avengers: Age of Ultron
Scenario 3: Captain America: Civil War
Scenario 4: Avengers: Infinity War
Scenario 5: Avengers: Endgame
He has access to all of his UNSC, Covenant, Forerunner weapons (two for dual-wielding weapons), equipment, and armor abilities.