Just saw this on Twitter, get in while you can!
After months of battle, the dust has settled and the top teams in the world are ready to face-off in the Halo World Championship 2016! Join your fellow Spartans around the world in celebrating this momentous event with the Challenger armor set and HaloWC emblem, available for free in the Halo World Championship REQ Pack.*
*Available 4pm PDT on 3/20/2016 through 9am PDT on 3/21/2016. Broadband internet required (ISP fees apply); Halo 5: Guardians game and Xbox Live Gold membership (sold separately) required.