It looks like Agent Locke will be accompanied not only by other Spartans, but there is also a celebrity face among the spartan team Osiris. Nathan Fillian is donning the spartan suit in the upcoming Halo 5: Guardians.
Halo 5 Opening Cinematic. Spartan Locke and the rest of Fireteam Osiris engage in an epic opening cinematic to Halo 5: Guardians. In the cinematic, the group receives UNSC orders to recover a high value target and are deployed to take on Covenant and Promethean forces in a fierce action sequence – the start to the most ambitious, robust and epic Halo campaign experience yet.