This is The Speed Demon, also known as Trent Smith. He possesses a Demon ability, housing all kinds of demonic abilities. He is a member of Avalanche, whom he works with Barret, Aerith, Tifa, Biggs, Wedge, and Jessie. In his past, he used to be a bully, and years later, he reunited with Tifa, when he decided to join Avalanche.