Who is Turin from The Silmarillion and what is their importance?

Turin is the son of Hurin and Morwen. He is raised by Thingol but leaves Doriath when he fears his mother's death. He later unwittingly marries his sister, Nienor. He kills Glaurung and then himself after learning that his wife is also his sister. He is called Elf-Man in Nargothrond as well as Agarwaen or Blood-stained. He is also refered to as Glaurung's Bane, Neithan, Gorthol, Mormegil, Wildman of the Woods and finally Turambar, the name under which he marries Nienor.