Matt serves as an admin of Team Aqua, a villainous organization dedicated to expanding the world's oceans. His unwavering loyalty to leader Archie originates from Archie saving his life, driving his actions throughout all documented media. In *Pokémon Generations*, Matt appears during the Seafloor Cavern crisis, urgently contacting Archie and Shelly about Primal Kyogre's awakening. He warns that its uncontrollable power risks global destruction, highlighting his role in monitoring existential threats for Team Aqua. Within the core series games—*Pokémon Sapphire* and *Pokémon Alpha Sapphire*—Matt steals critical items like Professor Cozmo's Meteorite and Devon Corporation parts. He aids Archie in hijacking Slateport City's Submarine Explorer 1 and repeatedly battles the player to obstruct Team Aqua's operations, confronting them at Mt. Chimney, Southern Island (attempting to capture Latias), Mt. Pyre, and the Team Aqua Hideout. After Kyogre's defeat shatters Archie's ambitions in the Delta Episode, Matt independently revives Team Aqua's goals. He ambushes Wally to steal a Key Stone, Mega Evolving his Sharpedo to assault Mossdeep Space Center. This fails when the player and Steven Stone intervene, resulting in Zinnia's Whismur stealing the Key Stone. Matt later reunites with Archie, reaffirming his commitment. In the *Pokémon Adventures* manga's Ruby & Sapphire arc, Matt operates as part of the "SSS Trio" alongside Shelly and Amber. He participates in kidnapping Mr. Stone and flooding a Mt. Chimney cable car to drown Sapphire and Flannery. Defeated by Sapphire, he is deemed unfit for a mission due to injuries. During Kyogre's rampage, he battles Winona using Sharpedo's Taunt to disrupt her commands but is defeated and abandoned at sea by Shelly. The Omega Ruby & Alpha Sapphire arc introduces a separate character using the inherited codename "Matt," who assists Zinnia and battles Sapphire at the Battle Frontier. Physically, Matt is depicted as tall and muscular. Early designs show him in a blue Team Aqua bandana, vest, and black shirt. His redesign features black headwear with blue "teeth," a torn suit revealing the Team Aqua logo on his chest, and rope accessories around his neck and waist. Personality-wise, he employs brutal battle tactics and exhibits fierce loyalty to Archie. He is noted as the most sensitive and nervous among Team Aqua admins, frequently striving to prove his worth despite setbacks.