Darkon, also known as Tekkaman Omega, is the primary antagonist and the overarching source of the alien invasion threatening Earth. His human identity is Conrad Carter, the eldest brother of the protagonist, Blade. Once a member of the Carter family aboard the space vessel Argos, he was captured and transformed by the alien Radam, known as the Venomoids in some versions. Unlike other captives who became foot soldiers, Conrad was converted into the Tekkaman Warlord destined to lead the invasion.

Darkon is a ruthless and determined figure, driven solely by the alien directive to enslave humanity by transforming the population into mutant beings. His personality is shrouded in a cold, commanding presence, as he operates from the shadows. He is physically tethered to the alien mothership, which lies hidden on the dark side of the Moon, and he cannot leave this base or resume a human likeness. He typically communicates with his subordinates through a holographic projection, maintaining a detached and ominous authority.

As the commander of the alien forces, Darkon orchestrates the entire campaign against Earth. He dispatches other Tekkamen, including his own transformed family members, to eliminate his renegade brother, Blade, and clear the path for the mothership to descend upon the planet. His primary motivation is the completion of the Radam's conquest, a goal intrinsically linked to his own monstrous existence. Darkon’s most significant relationship is with Blade; he is the ultimate target of his brother’s vengeance, revealed as the eldest sibling whom Blade must destroy. He also commands other key Tekkamen, such as Evil (Blade's twin brother), whom he upgrades to a more powerful form to serve as the final defense against the Space Knights.

A distinct aspect of Darkon’s development is his static yet escalating threat. He remains bound to the lunar base for most of the narrative, growing in power as he prepares to raise the spacecraft. In the final confrontation, he merges entirely with the base, becoming a gigantic, monstrous Tekkaman. In this grotesque final state, the only remaining part of his original humanity is his human face, lodged in the center of his massive chest.

Notable abilities include being the most powerful of the Tekkamen. While tethered to his base, the cables not only sustain his life but also enhance his power. In his final form, Darkon gains immense size and possesses additional abilities, such as deploying powerful tentacles and generating dark, shadowy copies of other Tekkamen to fight for him. Despite his overwhelming power, he is ultimately destroyed by Blade, who harnesses the power of a Blaster Tekkaman transformation alongside the crystal of his fallen brother, Evil.