Gotta Catch 'Em All (With a Twist)

(Just reached 10,000 views, and couldn't be happier, so thank you everyone and enjoy! I know I've been lacking lately on content, so if there's anything you'd like to see happen or if you just have some suggestions, please send me some feedback!)

Ash and Pikachu have returned home to Pallet Town. They've defeated countless trainers, received every gym badge, and has become the one and only Pokemon master. One day, he received a strange package from Professor Oak. He opened it up to find what seemed to be an infinite supply of strangely colored pokeballs and a note from the Professor. It said, "Now that you've become the Pokemon Master, it's time for you to become a different kind of master, so enjoy my new pokeballs!" Ash began to wonder just what Oak meant by what he said in the letter, and this is where our story begins.