Gon

About
Gon was sent to the land of outcasts called Shikoku (Death Country), at a young age, before he could learn kanji, due to having received a curse from a youkai. The curse gave him spikes that come out of his back and more physical strength, but in exchange he slowly started losing the ability to speak due to his tongue burning. Having spent a long time in Shikoku, he became a father figure for some of his inhabitants like Ryouma. He became one of the founding members of Takuga and together they were able to acquire less hostile land to live on until Rance conquered it. After freeing Ryouma from her curse, Ryouma tried to kill the youkai cursing Gon so that he could speak normally, but he decided to stay cursed because Ryouma lost some of her strength when the curse was removed and he wanted to be able to protect her.

Trivia

 * he is one of the only known humans to reach his level cap.