Roy has a huge one-sided rivalry with the Cinnabar Gym Leader, Shouju, that nobody really seems to fully understand but him. The backstory to it all starts before Roy was even born. His great-grandfather, Blaine, was the Cinnabar Gym Leader for a long time, and eventually became the mentor of Roy’s father, Green, in the years between the events of the Kanto games and the Johto games. When Cinnabar Volcano erupted, Blaine was offered the vacant position of Viridian Gym Leader, at least until his gym on Cinnabar was repaired or moved. However, Blaine recommended his apprentice, Green, for the position instead and, while he took some time off, Green remains as the Viridian Leader to this day.
After the Cinnabar Gym was rebuilt, Blaine returned to being it’s Leader, but after a few years he felt ready to retire. He offered his position to his grandchildren, Red and Leaf, and his by-now son-in-law, Green, but all of them either didn’t want to leave their current jobs or had no interest in being a Gym Leader. So, Blaine ended up looking through a wide variety of candidates for his position, but none of them felt quite right to him. In fact, he ended up finding the perfect successor by accident. While traveling in Johto, Blaine met Soumei and Shouju, the newly-returned-to-human Lugia and Ho-oh, by chance. The couple was still struggling to adjust, used to living in ancient times, but Blaine could tell there was a special spark about them – especially Shouju, who trained fire-types and seemed to have strong leader skills. He swooped in with an offer to come with him to Cinnabar, by now fully rebuilt, and see if taking over the gym would be a fulfilling new life for them.
As it turned out, Blaine’s instincts were spot on. Shouju took to being a Gym Leader like a fish to water (or perhaps more fittingly a phoenix to flame)… perhaps a bit too enthusiastically, but nobody could deny he was a strong trainer and provided a challenge for trainers on their League Challenge while also being able to manage the leadership that came with being a Gym Leader, looking after Cinnabar and its people. Shouju remains the Cinnabar Gym Leader through the fankid era, living on the island with Soumei and their son, Kanade. Now this is all fine and good, but Roy thinks it’s all wrong! Growing up, he learned about this whole story, and decided that what really happened was Shouju “stole the Gym from Red and/or Green”. No matter how many time his dads tell him they had no interest in becoming the Cinnabar Gym Leader and they both have no issue with Shouju being there, Roy is stubborn in his belief. (It doesn’t help that Green and Shouju have quite a rivalry going, both being arrogant and competitive, but it’s still a friendly rivalry between Gym Leaders and nothing deeper!)
Roy has made it his life’s goal to become the new Cinnabar Gym Leader and “oust the usurper”, but when he first went on his Kanto journey he was utterly wiped out by Shouju the first time he challenged him. To rub salt in the wound, Shouju isn’t exactly known for being comforting, so he simply told Roy all the ways he needed to improve before trying again. This only further strengthened Roy’s resolve and convinced him Shouju was basically the equivalent of the Demon Lord in his video games. Since that day, if someone brings up the Cinnabar Gym within Roy’s earshot he’s sure to go on a rant about his nemesis and goals of “freeing the gym from tyrannical rule”, so his traveling companions learn quick not to bring it up around him.
(As an aside, while I’m still developing what Kanade does/if he travels, you can bet Roy sees him as a rival as well – the son of the enemy!)
