TV Special
Description
The Great Demon Lord, also known as Beelzebub III, reigns as the supreme ruler of the Demon World, having unified it after previously governing one of its constituent nations. This past rule also secured his place among the elite Seven Deadly Sins.

His physical appearance remains largely concealed. He consistently dons a helmet featuring prominent side horns, complemented by long green hair and a black cape. Visual depictions typically show him from behind or obscure his face with a long fringe, preserving an aura of mystery around his visage.

His personality blends ludicrousness, forgetfulness, and warmongering tendencies. He initially commands the destruction of the Human World, driven by disdain for humanity's rapid proliferation. His irresponsibility surfaces when he dispatches his infant son, Beelzebub IV, to execute this task only to forget his own decree within a day, later realizing the child's incapability. His wife, Iris, brands him a "deadbeat husband," underscoring his unreliability. Despite these flaws, he reveals unexpected facets: an enjoyment of karaoke and a fiercely protective nature towards his family. This protective instinct erupts when he annihilates the entire Solomon Company and its elders in retaliation for their attack on Iris, explicitly citing her suffering as his motivation.

His background involves conflict and consolidation. Before unifying the Demon World, he ruled one of its nations. His reign faced a significant challenge from Lucifer, another former ruler contesting his throne. Though he emerged victorious, this conflict plunged the realm into widespread turmoil.

Within the series, he plays a pivotal role. He establishes contracts with powerful entities like Behemoth, utilizing enchanted tissues to summon demons from Behemoth's Pillar Division, and entrusts items to subordinates for delivery to Iris. His most consequential act is dispatching Beelzebub IV to the human world, initiating the core narrative. Later, he demonstrates capacity for change by rescinding the order to destroy humanity after witnessing bonds form between humans and demons, particularly between Tatsumi Oga and his son. His direct intervention culminates in defeating the Solomon Company's leaders, whom he deems responsible for corruption.

His abilities establish him as the series' most formidable entity. He wields immense demonic power, evidenced by defeating the other Seven Deadly Sins and his legendary battle with Satan that split the Demon World. He commands electrokinesis, generating and manipulating electricity for devastating attacks like the instantaneous Lightning Cannon, contrasting his son's more telegraphed abilities. He also creates specialized artificial demons, such as Tamapochi, designed for long-term roles. Furthermore, he is a skilled artist producing highly detailed portraits, though he undervalues this talent. His power is further emphasized by evading capture by the Solomon Company and effortlessly defeating other powerful fighters during Demon World training sessions.