In an interview with Eurogamer, 343 Industries studio head Bonnie Ross said the new Halo spartan starring in Halo 5: Guardians alongside series mainstay Master Chief is Agent Locke

Locke’s origin will be explored in the Ridley Scott produced Halo Nightfall series. The new character is to play a ‘key’ role in Halo 5 according to Ross. Halo Nightfall releases with the launch of the Halo: Master Chief Collection November 11th on the Xbox One. The collection combines the four core Halo titles remastered for Microsoft’s new console will run in 1080p resolution at 30 frames per second.

Source: EGM Now