Black Bolt is a member of Inhumans, a reclusive race of genetically altered superhumans and ruler of Attilan. he had powers in his voice, as his electron-harnessing ability is linked to the speech center of his brain. In Doctor Strange in the Multiverse of Madness, Wanda made Black Bolt unalive himself by removing his mouth…so his whisper literally backfired inside him.
In the Inhumans series, Black Bolt is training himself to intense mental training to prevent himself from uttering a sound, even in his sleep. In Doctor Strange 2, we see the variant version of Black Bolt, whose costume is accurate to the comic book.
In the film, Black Bolt is one of the member of the Illuminati, a group of heroes based on Earth-838, who monitors the multiverse threats. which is led by a version of Professor Charles Xavier (Patrick Stewart), and is made up of the likes of Reed Richards (John Krasinski), Captain Marvel (Lashana Lynch), and Captain Carter (Hayley Atwell).
Doctor Strange 2 is directed by Sam Raimi and stars Benedict Cumberbatch as Stephen Strange/Doctor Strange, Elizabeth Olsen as Wanda Maximoff/Scarlet Witch, Chiwetel Ejiofor as Karl Mordo/Baron Mordo, Benedict Wong as Wong, Xochitl Gomez as America Chavez, with Michael Stuhlbarg as Nicodemus West, and Rachel McAdams as Christine Palmer.
Doctor Strange in the Multiverse of Madness is now in theaters.