Delu Knight is a major antagonist from the anime Unofficial Sentai Akibaranger, where he serves as the Chairman of the Board for the villainous organization. His name is derived from the English word delusion, which is a central theme of the series, although he ironically expresses a strong disdain for delusions themselves. In terms of his position, he holds a higher rank than a regular sub-section chief, acting as a direct and powerful enforcer for Doctor Z, the primary antagonist.

Physically, Delu Knight is a formidable figure clad in knight-like armor. In the second season, his appearance is updated to feature darker armor and a reflective mask, distinguishing him from his original look. He is a skilled swordsman whose signature special attack is the Delusion Mirage, a powerful slash technique.

The character is defined by a code of pride and rivalry. Initially, he considers Takuma Tsuzuki, a temporary Akibaranger, to be his fated rival. However, due to a sudden change in the show's narrative direction, he shifts his focus to defeating Nobuo Akagi, the leader of the Akibarangers. This desire for a worthy opponent shows a sense of honor, as he once deliberately damaged his own chest armor to handicap himself, demanding a fair final battle with Akiba Red. Despite his villainous role, a brief mention is made of him having a fiancée, adding a small, humanizing detail to his character.

His role in the story is that of a powerful field commander and a living embodiment of the show's meta-narrative. He is summoned by Doctor Z after the latter eliminates the remaining sub-section chiefs. As the first season approaches its finale, Delu Knight seizes control of the evil organization by shooting Doctor Z and his daughter Malshina, declaring himself the new leader. He takes Sayaka, a friend of the heroes, hostage to force a confrontation, desperately trying to trigger the tropes that would lead to a conclusive final battle and, therefore, the end of the Akibarangers' world. When the heroes refuse to participate in these climax tropes, a resurrected Delu Knight pilots the giant robot Boomerang Titan to destroy Akihabara, only to be accidentally defeated when a thrown soda can redirects his own mecha's weapon back at him.

The character's development is heavily influenced by the show's self-aware retconning in the second season. In the revised timeline of Season Tsuu, his original death is changed; he is instead killed by the Ludicrous Cannon, a powerful weapon of the Akibarangers. Later in the second season, he is revived by Malshina using the death of another character, Kameari Alpaca. Upon his return, Malshina manipulates reality to reverse the narrative concepts of "victory" and "defeat" flags, making Delu Knight temporarily unstoppable until Akiba Red deduces the trick and re-establishes the proper flags for his defeat.

In terms of notable abilities, beyond his swordsmanship and the Delusion Mirage attack, Delu Knight has demonstrated the power to summon other monsters. In the second season's recap of the first season's events, he creates a portal to the underworld to bring back three sub-section chiefs. He is also a capable pilot of the giant mecha Boomerang Titan, engaging in a colossal robot battle with the heroes. His combat prowess is established as being far superior to the Akibarangers upon his first appearance, forcing them to rely on narrative loopholes rather than direct force to overcome him.