Who is Rincewind from The Light Fantastic and what is their importance?

Rincewind is the main character of the novel. He lives in the city of Ankh-Morpork and is training as a wizard at the Unseen University. As a student, he opened the Octavo book and the eighth spell entered his head, destroying the other spells he had learned. From then on, he had no chance to succeed as a wizard and ended up failing miserably. Once thrown out of the University, he meets the tourist Twoflower and shows him around the world for what is said to be a large sum of money.