There was some speculation earlier this month that Agent Locke will be the main character of Halo 5: Guardians. It turns out Master Chief will still be the main man of the game.
As it was revealed earlier, the voice actor for Agent Locke (Mike Colter) revealed some of the early plot details of Halo 5: Guardians during an interview with X-One magazine. He said that Agent Locke will be a “primary character” in the game and players will control Locke as he is trying to find Master Chief’s whereabouts. This led to some suggesting Master Chief does not have a big part in Halo 5: Guardians.
Halo 5: Guardians developer Frank O’Connor posted on Reddit to clarify to everyone who truly is the main character of the game. He said Colter just said Agent Locke will only be a “primary character“. As for Master Chief, he “is the main character and hero“.
He also reiterated there isn’t any current plans to make a main entry Halo game without Master Chief in the main role. He said “NO. The end“, when asked if there was chance of that happening.
By the sounds of this, Halo 5: Guardians will be similar to Halo 2 as you controlled two important characters. In Halo 2, the Arbiter had a big role as well as Master Chief.