Sorrow of Teash
From Halopedia, the Halo wiki
The Sorrow of Teash is built upon the chassis of the standard Brute plasma rifle, though features a white-and-yellow striped paint scheme over the top. Mechanically, the weapon has been upgraded with better accuracy and upgraded heat dissipation.
Following the fall of the Sacred Promissory, Jiralhanae warlords in command of post-war fleets and colonies have moved to procuring the services of expert weapon smiths across known space. The Sorrow of Teash is named after Teash, one of the three natural satellites orbiting Doisac.