Matt Horner was tired of his boring life and joined The Sons of Korhal where he soon mastered being a pilot and graduated with honors and worked with Jim Raynor, whom he admired for his bravery and loyalty.
Matt Horner gained a good reputation as the good pilot he was, transporting supplies and troops for the Sons of Korhal between the star systems. He later worked with Jim Raynor who inspired him for his bravery and loyalty. The inspiration, and his principles against torture to innocents made him quickly follow Jim Raynor's path, and turned his back on Mengsk, to later become the captain of the Hyperion after Raynor's men seized the battle cruiser.
Over the years, Matt has been working with Raynor and his crew, and believes in his heroism as they move on to new campaigns. He is a diplomatic, and a loyal assistant, as well as a good strategist, and an excellent pilot.
Links
Starcraft2.com - Source