The newest Halo 5: Guardians multiplayer "season" is now underway. As announced by the Halo Twitter channel, the January-February 2017 season has kicked off and you can earn the emblem below by completing your placement matches.
You must complete 10 of the aforementioned placement matches to determine your Competitive Skill Rating (CSR) and unlock the emblem. There are seven CSR ranks, including Bronze, Silver, Gold, Platinum, Diamond, Onyx, and Champion. You can visit your Service Record page on Halo Waypoint to see your Ranked Arena playlist statistics for every season so far.