Alternate forms of matter
A mineral responsible for refrigeration, arctic landscapes, and hot springs across the world.
Part of my series on pseudo-magical world building
An elemental substance of tremendous purity and power.
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.