The Ancient Warforged (Eberron Character Sheet)
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The Warforged was crafted out of 5 separate materials, one gold, one silver, another jade, a dark metal that seemed to absorb light and finally a metal that seemed to be made of iron but not, the last was in the least quantity.
The Jade Skull in its chest seemed to be part of the whole rather than some kind of Docent like attachment. Confirming through messengers he narrowed the golden metal down as it being called Orichulum, and the dark metal was rumored to be called Soulsteel.