Niessin: NIGH-sin
Welsh: "The Nice One"
Son of Penardun and Eurowysedd, he is the opposite of his brother Efniessin. Niessin, though little is written about him, is said to be the peacemaker of the Children of Llyr, but he is ignored by the family, who goes to war with Ireland at Efniessin's instigation, according to "Branwen uerch Llyr" in the Mabinogion.