By Daniel Chavkin The defending welterweight champion is the newest Marvel cast member. The Marvel universe is adding a UFC champion. According to Damon Martin of MMAFighting.com, UFC welterweight champion Kamaru Usman will appear in the upcoming Black Panther sequel, Wakanda Forever. The movie is scheduled to premiere on Nov. 11, and it is unclear what role Usman has. In the meantime, Usman is expected to face Leon Edwards in August to defend his title as welterweight champion. In his career, Usman is 20-1-0 as a UFC fighter and earned the welterweight championship by defeating Tyron Woodley …