History
T'Challa, the younger son of King T'Chaka of Wakanda, was severely injured during the "Trial of the Panther" from which the protector of the nation is selected.
His older brother M'Baku found T'Challa bloodied and near death but derisively called him a fool for attempting the trial.
Later, M'Baku added that he, not T'Challa, should have taken the trial. Angry that his father had decided to share Wakanda's technology in exchange for America's help in saving T'Challa's life, M'Baku left Wakanda. To save T'Challa, T'Chaka turned him over to S.H.I.E.L.D.'s Weapon X program.
Over a year later, a healthy T'Challa, in his full Black Panther garb, had enhanced speed, strength, night vision, and healing ability. Additionally, he could summon short, cat-like Adamantium claws from his knuckles by balling his hands into fists. T'Chaka became outraged upon learning that S.H.I.E.L.D. now considered his son an asset of the U.S. and S.H.I.E.L.D.
He subsequently contacted M'Baku a letter, claiming that M'Baku, not T'Challa, was the titular "favorite son," and implored him to return.[1]