KO was upset that he couldn't level up. Mr.Gar was a level 11, Enid a level 3, Rad a level 2, heck, even Dendy was higher than him. So he decided to become a villain. He would work under some familiar villains, so he could learn how to be one. He knew that if anybody who was a hero knew about this, he would be shunned, so he's keeping it a secret. To keep his family and friends safe...
5 parts