Shadesteel golem

A shadesteel golem was a construct made from metal mined in the Plane of Shadow. It was often used as a guardian, in conjuction with undead.

Description
Shadesteel golems were made from a matte material that seemed to absorb light. Its long arms ended in sharp metal claws, and mist seemed to fill the space between its parts. It did not have a neck, but its head was skull-like. The construct hovered over the ground silently, disturbing nothing in its passage.

Behavior
Shadesteel golems always returned attacks made against them if uncommanded, otherwise following commands as all constructs did. They always fought to their destruction.

Combat
Besides its normal attacks, these golems were capable of unleashing waves of negative energy that grievously damaged all living creatures in their vicinity, healing undead creatures in the same attack, about two or three times per minute. Their resistance to magic was absolute, invariably defeating any spells other than those causing effects related to light and shadow, which sped it up or healed it respectively. They were also difficult to see clearly in any condition other than bright daylight, blending into any nearby shadows or even their own.

Creation
Besides the construction of the vessel, which required large amounts of steel tempered with shadow-liquids and awesome armorsmithing skills, the magical ritual to create the golem called for a mage capable of using all of the most powerful spells, including energy drain, geas/Quest, limited wish, and shades.

History
The first to create those golems were the wizard-kings of Imaskar. Others had since attempted to plunder the secret of their creation from their ruins, but it was unknown whether they succeeded or not.