Testarossa, also known as Blanc, is one of the Primordia's that joined Tempest after Diablo recruited her and the one who caused the infamous "Lake Shore Dyed Scarlet Incident". She is the military attaché and the Minister of Foreign Affairs within Tempest, as well as a leader of the Black Numbers along with Ultima and Carrera, and is counted as a member of Rimuru's Twelve Guardian Lords.