Come forth, the world weary, be assured that the blessed steel will guide you into the Green Vales! The wondrous Sting will herald your entry into the blessed realm.
A powerful empire, macabre and violent. Now gone, a victim of their own folly.
The Hanset are a sleeping giant of a race. Once the owners of an empire of Alexandrian proportions, they new reside in their hidden sub-tropical home, living the simple lives of tribesmen. Though bereft of metal tools, they have adapted to their forest home and it to them. Though their empire is long gone, they still hold onto the seed of its greatness.
A powerful, maritime people, brought down by the foulest Necromancy.
A people of systematic inhumanity - beyond bloodthirsty.
Teenagers who run away from home to live in the wilderness may become feral. As they become more and more feral, they gain some supernatural powers (a la Peter Pan - ability to fly, things they imagine come true - possibly quite powerful), but at the expense of their humanity and ability to speak, comprehend complex subjects, etc. Maybe they have a leader: the most feral of them all.
A regression into a fantasy childlike state.