Crystal stricken

Far below the Spikes, farther then any have dared to dig, hide minerals and metals with legendary properties. These caves are considered a hidden treasure trove by all miners of any worth. But only a few know that the caves hold more than rocks and crystals, they hold life. Little do the miners know that the creatures of their horror stories are from that place. Calling them monsters would only be a matter of perspective. In reality the so called horrors are just the folk that have lived there and thus bare it's unique curse. The victims have strange semi-translucent crystals growing from their bodies. For many that would be a sight worthy of a tale.
 

Crystal curse

You have a naturally formed armor of crystals growing from your body, giving you an AC of 17. This armor class gains no benefit from dexterity. Furthermore you are resistant against non-magical slashing and force damage.  

Magic hungry minerals

You are unable to wear armor. Furthermore you are vulnerable to non-magical bludgeoning damage and magical effects only last for half the time when cast on you.