The Black Cross Führer is the supreme leader of the Black Cross Army, the primary antagonistic force in Himitsu Sentai Gorenger. This entity is an ancient and powerful being, often referred to as a Machine Monster due to its seemingly invincible nature and true form as a sentient alien machine construct. The Black Cross Führer is intrinsically linked to the Black Cross Castle, a mobile floating fortress from which it commands its forces, and it is revealed that the Führer is in fact part of the castle itself.

In terms of personality, the Black Cross Führer views humanity with utter contempt, considering the species inferior and fit only for subjugation or destruction. It rules the Black Cross Army with an iron fist, addressing its subordinates with commanding disdain and measuring their value solely by their success in furthering its goals of conquest. The Führer is known to be impatient with failure and quick to anger over incompetence, demanding absolute obedience and punishing any defiance with wrath. This ruthless and efficient cruelty defines its leadership style, treating even its high-ranking generals as ultimately expendable assets in its grand scheme.

The primary motivation of the Black Cross Führer is total world domination and the enslavement of humanity. To achieve this, it seeks the complete annihilation of the international defense organization EAGLE and its special operations team, the Gorengers, who stand as the only significant obstacle to its plans. The Black Cross Army, founded by the Führer, is an international terrorist organization that utilizes advanced technology, cybernetics, and even supernatural magic to sow chaos and eliminate opposition, all under the Führer's iron-fisted rule.

Throughout the series, the Black Cross Führer maintains a mysterious and remote presence, often keeping its true identity secret even from its own generals by initially wearing a pointed white hooded robe. Its role in the story is that of the ultimate evil commander, orchestrating the attacks on EAGLE and the Gorengers from the safety of the Black Cross Castle. While it delegates much of the direct combat to its various generals and mask monsters, the Führer's will drives the entire conflict. Key relationships with its subordinates are hierarchical and transactional; the Führer employs a succession of generals, including Sun Mask, Iron Man Mask General Temujin, Volcano Mask General Magman, and Commander-in-Chief Golden Mask, each recruited from different global operations to destroy the Gorengers. The Führer's interaction with them is consistently one of a demanding master expecting results.

The character undergoes a notable development in its presentation. For the first half of the series, the Black Cross Führer remains a shadowy, hooded figure, adding to its mystique and menace. As the series progresses, it eventually discards this disguise to reveal its true form, an inhuman alien machine construct that confirms its nature as more than a simple flesh-and-blood villain. This revelation underscores the character's identity as a supernatural or extraterrestrial entity rather than a human in a costume.

The Black Cross Führer possesses a wide array of notable abilities. It is incredibly intelligent and has numerous supernatural powers. It cannot be easily killed by any conventional weapon and is vulnerable only to a specific weakness related to the Cassiopeia constellation. One of its most distinctive abilities is the power to disguise itself as a human, and it can assume either male or female form, allowing for infiltration and deception. In its final confrontation, the Führer proves to be a nearly invincible opponent, ultimately requiring the combined power of all five Gorengers launching their ultimate attack, the Cassiopeia Five Star, to finally defeat it.