TV-Series
Description
Lon Beruk is a Darkling from the Underworld, distinguished by teal skin, pointed ears, black hair, and a prominent X-shaped scar across his face. He was once the Underworld's greatest swordsman, but after ten years developing a devastating technique, he destroyed both his weapons and his arms. A seventy-year recovery followed, after which he turned his focus to blacksmithing, spending the next one hundred years forging his signature Celestial Emperor dual blades.

His extraordinary skill attracted the attention of the Dark King Vearn, who recruited him. During his service, Lon Beruk crafted several significant weapons, including the Staff of Edacity for Vearn—a creation he considered his worst, yet which became one of the Dark King's most dangerous tools. He also forged the Dark Armour Blade and the Dark Armour Spear in this period.

Nearly ninety years before the main events, Lon Beruk defected from Vearn's army. While departing the castle, Mystvearn slashed his face, leaving the distinctive scar. Lon Beruk stated he allowed the first strike out of respect for humiliating Vearn by leaving, but warned he would counter any further aggression. He then relocated to the human world, settling in a cottage near a town and providing weapons to Popp's father.

His involvement with the main protagonists began when he was introduced to Dai after a tournament at Romos. Initially unimpressed, he deemed the youth worthy upon learning Dai had shattered a Dragon Knight's sword using the Dark Armour Blade, one of his own creations. He agreed to forge a new sword for Dai on the condition the hero procure orichalcum. Using orichalcum from the Crown of Champions, Lon Beruk crafted the Sword of Dai, insisting the hero be present for the entire forging process.

After a major battle, he repaired the weapons of Dai and Hyunckel, noting the arms would eventually self-repair but choosing to train the duo himself. He expressed particular admiration for Hyunckel's swordsmanship, noting it might have surpassed his own. When the Sword of Dai and the Dark Armour Spear returned to him after their owners' defeat by Vearn, he interpreted it as the weapons requesting upgrades. Setting aside his pride, he was persuaded to craft new arms for every member of Dai's party to prepare for the final battle.

Lon Beruk participated directly in the conclusive conflict against the Underworld's forces. He confronted Mystvearn, their battle ending in stalemate as both held back their full power. After Mystvearn's departure, he faced the transformed Hyper Zaboera. When Nova offered to sacrifice his life to create a powerful attack, Lon Beruk intervened. He declared that Nova's courage was enough and that he, as the master smith, should be the one to sacrifice. Wielding his Celestial Emperor blades, he defeated Hyper Zaboera but sustained severe injuries that cost him both hands. Following this, Nova pledged to serve as his hands for all future smithing work.

In the aftermath, he assisted in containing the Vearn Pillar Black Core over Roroy Valley. Later, he observed that Dai was likely still alive, evidenced by the gem in the Sword of Dai continuing to shine, and he subsequently took on Nova as his blacksmithing apprentice.