In Forge Of Fury, a group of dwarven adventurers, including both of the Lazarus Project, entered Khundrukar. Braving Arundil's possession attempts and ghostly fear, they slayed him in his halls, and he was given a last glimpse at the success of his project before disappearing for good.
A powerful Dwarf transmuter who dabbled in darker magics, Arundil Dhaldohr was the chief Wizard of Khundrukar and one of Durgeddin the Black's most trusted advisors. He grew up in Mountain's Meet, practicing arcane matters until his home fell to raids by Orcs; following Durgeddin's operations, he joined him on a decades-long revenge. Orehand assisted with mining out the Stone Tooth and setting up a base from which to wage war. While his friend handled military operations and weapon forging, Arundil was chiefly tasked with creating defenses for Khundrukar and adding Spells to Durgeddin's masterworks.
Some of these defenses were the implementation of traps and a door to the Foundry only accessible via magic key. Additionally, he created many Animated Objects that would attack non-dwarves in the the Foundry, including tables, chairs, Animated Armor, and a gargantuan Rug of Smothering. Arundil's favorite work, however, was in attempting to recreate an Epochal Artifact. However, the Thrakûr-Gundak was kept in Brazenthrone, and was inaccessible to the wizard.
Though he could not replicate the artifact's power, he created two prototype Synthborn to eternally defend their home: branded as Mk. I and Mk. II, they became known as the "Lazarus Project". Both of these automatons remained unfinished, however, when orcs and Trolls stormed Khundrukar. The two continued to respectively live as Lazarus of Khundrukar and Lazarus of Khazalet.
When evidence of the orc-tunnel into Khundrukar was found, the Smith's War was coming to a close. Arundil grew desperate to create further defenses, and attempted to summon a Fiend. He conjured a Succubus named Idalla to his den; he believed he could bind Idalla to his service, and install her as a permanent protector of the Foundry. However, he misjudged her own fiendish abilities, and she quickly overpowered his will. She toyed with him cruelly until finally draining his life force, resulting in him becoming a Ghost that haunted Khundrukar's halls.
For nearly a century, Arundil haunted the northern halls, attacking and terrifying the thieves and interlopers who would come to rob his tomb.