His skills as a duelist are superior to those of even Astral. For the sake of the treatment for his younger brother Haruto, he became a Number Hunter under the command of Mr. Heartland.
He can come across as arrogant due to being highly prideful and rejecting the help of anyone else, but what is essential is that he is a gentle older brother who worries about his younger sibling. As his brother Haruto has changed drastically, he is now preparing himself to make any necessary sacrifices for the sake of healing him, and, perhaps because of what he has to do, he has completely distanced himself from everyone around him.
When he hunts, he uses Photon Change to employ Numbers without suffering their side effects, but it instead imposes a great burden on his body. He uses Photon Hand to collect Numbers from his opponents, but the only technology available for him to do so also takes the souls of his targets.
During duels, he uses Photon Decks, which were created by Doctor Faker using the astonishing potential of science from another world. His ace monster, Galaxy-Eyes Photon Dragon, gained some of Haruto's powers, which manifest as Neo Galaxy-Eyes Photon Dragon.