Short answers, pulled from the story.
Alex was created by designer Yasuda, known professionally as Akiman, early in the development of the Street Fighter series. Yasuda intended Alex to be a simple hero to allow supporting cast members to be more flashy.
Yasuda developed Alex's facial features based on the appearance of French actor Christopher Lambert. Artist Kinu Nishimura was particularly fond of Lambert's look and influenced this design choice.
Alex made his first playable appearance in Street Fighter III: New Generation. He entered a narrative driven by personal loss and vengeance after his mentor Tom lost a fight with Gill.
Alex entered the third World Warrior tournament with the specific intent to kill Gill. This decision was prompted when Gill sent Alex's mentor and legal guardian Tom into a hospital after their fight.
Alex won a pro-wrestling tournament and fought in a tag-team exhibition match before a Black Moon detonated over New York City causing a blackout. He later gave a porcelain chess piece to Dhalsim after realizing Dhalsim was not a mugger.
Alex reappears as a playable character in Street Fighter 6 having moved to Metro City where he ends up becoming a heel wrestler. This shift in persona reflects his ongoing journey of self-discovery and adaptation to new environments.