Complex sentence: Prince Colwyn is found and nursed by Ynyr, the Old One, who tells him the Beast can be defeated by the "Glaive": an ancient, magical, five-pointed throwing weapon.
Split into simpler sentences: Prince Colwyn is found and nursed by Ynyr, the Old One. Ynyr tells him the Beast can be defeated with the "Glaive", an ancient, magical, five-pointed throwing weapon.