Cosmo Phobas was Rizon Phobas's firstborn child and the Second Leader of the Dragonlords after Xander Huorath's death.
Despite their title, Rizon notes in her writings that Telemok Arkelander was the real 'leader' behind-the-scenes until their death during the final battle at Praxys.
They are buried at the Necropolis at Telemok, alongside the other Dragonlords.