Rage Armor

Rage Armor is the spiked blackened plate mail that Berserkers wear into battle. It greatly increases its user's combat capabilities and makes them immune to pain when activated. The armor sends spines into its wearer's body that alter their nervous system, shutting down all sensation both physical and mental except for sight, sound, bloodlust, and rage. Most who use the armor become completely dominated by it, going into a frenzy and killing anything that moves, foe and ally alike.
It is believed that Bersekers actually have no use for their rage armor as they are capable of putting themselves into the enraged state it produces without it, however, they choose to bring the armor into battle so that any opponent who is powerful enough to defeat them may end up donning the armor and continuing their wrath.