Chardalyn Berserker

Chardalyn Berserker
Chardalyn berserkers are Reghed nomads who wield weapons made of chardalyn, specifically ones suffused with demonic magic (see the sidebar on Chardalyn|IDRotF|0|Chardalyn). This exposure has transformed them into fiends. They shed their heavier protective clothing and embrace the frigid cold, allowing frostbite to ravage the exposed parts of their bodies, with only their faith in the Frostmaiden keeping them alive.
Chardalyn Weapons
A chardalyn berserker wields one or more weapons made wholly or partly out of chardalyn that has been tainted by demonic magic. Battleaxes, flails, javelins, and spears are favored weapons, though other weapons are possible.
A character who claims one or more of these weapons can be corrupted by them. Each day at dawn, roll a d6 for each such weapon in the character's possession. On a roll of 1, the character must succeed on a 13 Charisma saving throw or become an evil NPC under the DM's control, unless the character is evil already. This alignment change can be undone by any magic that ends a curse, but after ten days, it can be reversed only by a wish spell or divine intervention.
A creature wounded by one of these chardalyn weapons can feel a sudden sickness creep over them, but it passes quickly.
Chardalyn Madness
Prolonged contact with the demonic magic imprinted on the chardalyn has afflicted the berserker with a form of madness, causing the berserker to believe that its weapons are conduits through which it can speak to a demon lord or other dark power, as well as channel its rage. If the berserker's madness is cured using magic that removes the effects of madness, the berserker loses its Chardalyn Madness trait but retains its chaotic evil alignment and other qualities. Further exposure to the demonic magic causes the berserker's madness to return, however.