Riley made his first appearance in the anime in Steeling Peace of Mind!. He is a Trainer specializing in Steel-types and is currently staying at Iron Island for the study of said type. Due to the strange behavior of the Steel types on the island due to Team Galactic, he decided to investigate it with the help of hisLucario.
In Saving the World From Ruins!, it was revealed that Riley is training to be an Aura Guardian with his Lucario and as such he is able to use Aura effectively. He was then shown to be an advanced user of Aura.
After Team Galactic planted bombs under Iron Island, Riley and his Lucario trapped the explosion using their Aura and sent it away from the island, foiling Team Galactic's plan. Later he decided to help Professor Carolina in the study of the island so that he could get to know it better.