Introduced in Black Panther, Winston Duke’s M’Baku, the leader of Wakanda’s Jabari Tribe, was initially shown in an antagonistic light, as he didn’t feel that T’Challa was worthy of leading the African nation and challenged him for the crown in ritual combat. T’Challa emerged victorious, though rather than kill him opponent, the king of Wakanda persuaded M’Baku to yield.
Article source: https://www.cinemablend.com/news/2492458/winston-duke-reveals-avengers-endgames-deleted-mbaku-scenes