Rudolph was just your everyday human, making music in his studio with dreams of making it big. But everything changed when he woke up on four legs, as a tiny Rockruff in a world completely inhabited by Pokemon!
He was found by a happy-go-lucky partner who convinced him they could become a Rescue Team organization, and found himself uncovering all sorts of conspiracies in the strange world... A world being threatened by a massive meteor.
Upon making their way to Sky Tower, Rudolph and his partner defeated Rayquaza and earned their right... but unfortunately, the battle had done too much. Not even Mega Evolving gave Rayquaza the power to destroy it. In a final, desperate act, Palkia was called upon to merge the doomed world with Rudolph's, and take it out of the meteor's path.
Rudolph would again wake up, in what he could only describe as a new body again. This time, his human form had merged with that of a Lycanroc, leaving him heavily muscled but also furry. And not just him, but several people were now anthros, as well as some Pokemon having become humanoid. Everyone's memories were tweaked to know about the event, preventing mass chaos, but it did take people time to adjust.
With his new look, Rudolph returned to his career, finding the sharp canine hearing to be a useful tool in making his music stand out even more. And better yet, not only did his partner find him, but he also got a handsome pleasure companion out of Rayquaza for a debt.