Short answers, pulled from the story.
Vega was designed by Mizuho "Katuragi" Kageyama, working under character designer Akira "Akiman" Yasuda and game director Akira Nishitani. The concept emerged from a need to represent Spain in the roster after Japan's slots were already filled by karate and sumo fighters.
Vega wears his mask to protect his face, a trait the designers built on Shakespeare's portrayal of Spaniards as excessively vain through Don Adriano de Armado in Love's Labour's Lost. The development team used this as the psychological foundation for Vega's backstory, extending it into his deep hatred of visual ugliness.
In Japan, the character's name is Balrog, chosen because director Akira Nishitani felt it sounded strong. The name Vega was assigned in Western markets as part of a last-minute shuffle prompted by legal concerns over a boxer character whose name resembled that of real-life boxer Mike Tyson.
Vega first appeared in Street Fighter II: The World Warrior in 1991 as the second of four boss opponents near the end of the single-player mode. He became a playable character starting with Street Fighter II: Champion Edition, the second version of the game.
Jay Tavare played Vega in the 1994 live-action Street Fighter film, and Taboo played him in Street Fighter: The Legend of Chun-Li. South African country singer Orville Peck is set to play Vega in an upcoming live-action production directed by Kitao Sakurai.
Vega uses a personal fighting style that combines Japanese ninjutsu with Spanish bullfighting, earning him the nickname "Spanish Ninja." His signature weapon is a three-pronged claw, conceived by the designers as a replacement for the sword a matador would traditionally carry.