is the Gym Leader of Stow-on-Side's Gym in the Galar region. He is a mysterious boy that has an emotional bond with Ghost Pokémon and wears a mask.
went to Shoot City Station to catch a train to Lateral Town. After seeing a masked boy drop a ticket, they decide to get on the somewhat creepy-looking "Ghost Train" in order to return it. That boy turned out to be Allister
then went to visit Allister
in Lateral Town, in order to make Gangar Kyodaimax. Allister
tells them that Kyodaimaxing Ash's Gengar
required having it drink Max Soup made from Max Mushrooms and that to gather the Max Mushrooms, they'd have to get them from a forest where there was a lots of unique Ghost type Pokémon.