Soulsteel is known as the "Sorcerer killer" metal, made from Dragonsteel. It has a higher iron and lead content than Dragonsteel, with iron and lead being powerful mana destabilizers. Its toxicity and efficiency of killing high-energy creatures is what deemed it illegal to create and own. Nobody knows how it is created, except for the Al'adhaa Estate, who invented it. However, it is now known that high enough electric power [such as that of a natural lightning bolt] can destabilize Soulsteel and deem it inert.
Soulsteel is an extremely brittle metal alloy, and is only used by electroplating other metals to give them an enchanted edge. All Soulsteel weapons have a dull edge. It is ineffective for use in armor.