Ocanthus

Ocanthus was the fourth layer of Acheron. An infinite, perpetually dark expanse, it was filled with razor-sharp shards of black ice that flew around at high speeds.

Geography
Ocanthus had an icy cold atmosphere of breathable air. However, the raging storm of shards in Ocanthus was extremely dangerous. They were as sharp and possessed the same ability to decapitate creatures as vorpal blades.

Some of the shards were large enough to generate their own gravity and to support structures. They all originated from a seemingly infinite boundary of black ice located at the bottom of the layer. It was believed that all shards were chipped away from this boundary, and successive collisions broke them down progressively into smaller shards, then needle-sized pieces, and finally to dust.

Rumors & Legends
The exact nature of the endless black ice at the bottom of Ocanthus was largely unknown. It was debated whether it was a true boundary or just a barrier between the layer and some deeper, unknown fifth layer of Acheron. Others maintained that it could be just one more enormous shard like the others, but whose boundaries were unknown.

It was said that the black ice was either the destination or the source of the River Styx. The ice was rumored to hold all the lost memories that were stolen by the river. In addition, such memories were even said to be easily accessible by as simple an effect as a knock spell.

Notable Locations

 * Zoronor, also known as the City of Shadows. A mostly deserted city inhabited by bladelings.

Inhabitants
There were very few inhabitants that could survive the hazards of Ocanthus. Besides the small population of bladelings in Zoronor, the layer was also home to inhabitants from Mechanus who operated mining colonies in some of the shards.