Jonathan Majors is Kang the Conqueror, the new Thanos-level big bad in the Marvel Cinematic Universe; we get our first good look at him in “Ant-Man and the Wasp: Quantumania” after seeing one of his more peaceful variants in the Disney+ “Loki” series and possibly hints of him elsewhere. Interestingly, the first Council of Kangs’ arch-enemy wasn’t the Avengers or …