Though he arrived much later than some of his peers in competitive battling, he was a trainer that showed great promise and quickly rose to fame in Europe. He spent much of his early childhood watching his half-brother Alistair compete in tournaments and wanting to follow his footsteps in raising Fairy-types, something Alistair was happy to oblige. There was a time where he was number one in all the standings and the distinction changed his personality over time. His peers, who used to admire him, suddenly considered him to be snobby and self-centred. But a new generation of trainers entering into competitive battling forced him to change his tune when the losses kept stacking and he was grilled by the press and his fellow trainers. Now in his thirties, he's matured into a trainer who takes his losses in stride and speaks with wisdom to young and budding trainers.

Arthur is specially trained for the use of Fairy and Ghost-types, but he keeps an additional multi-type team for generic tournaments. He dreams of becoming part of the UK Elite Four one day. Arthur had very strained relationships with his half-brothers growing up but things have since cooled between them. He is not on speaking terms with his father, but remains close to his mother. She gifted him his first Pokemon, a Sinistea, who is now his ace as a Polteageist.