Overlord is a major antagonist of the anime Akū Daisakusen Srungle, introduced in the later portion of the series. It is described as the collective will of the ancient Crime aboriginals, the first race to settle the region known as Subspace, or Akū, after arriving from beyond the seven-thousand-star nebula in the constellation Cetus approximately thirty-three centuries before the story begins. The ancient Crime people built a civilization in Subspace, but were later massacred by invaders centered on people from Earth. To contain the surviving will of the ancient Crime people, the invaders constructed the great artificial city of Galactown at the center of Subspace, which eventually became the capital of the UGS Federation. Overlord therefore carries within itself both the memory of a destroyed people and the secret behind the creation of Subspace and Galactown.

In terms of motivation, Overlord is defined by revenge and the restoration of ancient Crime rule over Subspace. Its actions are not spontaneous; the series presents Overlord as having devised a long-term program of reconquest, timed to coincide with celestial anomalies and prepared many centuries in advance. Everything that unfolds in the later conflict is presented as part of this prearranged design.

Within the story, Overlord is the hidden architect behind the criminal syndicate Crime. The founding of Crime itself is revealed to have been arranged as an instrument of ancient Crime vengeance, and the rise of the executive Volklazer, including his strengthening of Crime's military forces and his coup against the organization's original leader, unfolded according to the program laid down by Overlord. The narrative begins as a struggle between the special defense team Gorilla and the crime syndicate, escalates into open warfare between Crime, the Gorilla team, and the forces of the UGS Federation, and eventually becomes a struggle over Overlord's plans for revenge and the secrets of Subspace's origins.

Overlord's key relationships are defined through the organizations and people it sets in motion. It works through the Crime organization, particularly through Volklazer, whose coup and subsequent military campaign serve the larger design. Overlord stands in opposition to the Gorilla team, led by Captain Chance, and to the UGS Federation that represents the order built by the invaders. Its presence reframes the entire war as the working out of an ancient race's claim to its lost homeland.

In terms of development, Overlord remains a distant, hidden influence for most of the series and only emerges as an active force in the final stretch of the story. Its emergence transforms the conflict from a conventional struggle between criminals and defenders into something larger, revealing that the war was planned long before the current generation of characters was born and tying the fate of Subspace to the unfinished business of its first inhabitants.

Overlord's notable abilities lie less in direct combat and more in the scale and patience of its influence. As a collective will, it can encode its purposes into long-running programs that steer organizations and individuals across generations, orchestrating coups, wars, and even the founding of a major criminal empire without acting directly in most events. Its power is expressed through the unfolding of this design, making it a threat defined by the certainty of its long-prepared plan rather than by any single display of force.