Ekubo is a self-styled upper-class evil spirit whose earliest memory is existence within a cemetery, lacking any recollection of a human life. For decades, he commanded a gang of spirits until a confrontation with the powerful Mogami nearly caused his exorcism. His initial ambition focused on becoming a god worshipped by humanity, leading him to found the cult "(LOL)" or the Smile Religion. Using hypnosis and possession, he gathered followers to harness their collective faith for power. This pursuit brought him into conflict with Shigeo Kageyama, whom he tried to brainwash. Following a decisive defeat and exorcism, he reformed in a diminished, wispy state resembling a greenish floating energy bulb with a detailed face featuring a prominent nose and lips. Red circular marks appear on the faces of those he possesses, serving as his signature trait. After his defeat, Ekubo aligned with Shigeo Kageyama, ostensibly to exploit the boy's immense psychic potential for his godhood goals while promising to avoid harmful acts. He demonstrated perceptiveness early, accurately identifying psychological traits like Teruki Hanazawa's superiority complex and Ritsu Kageyama's inferiority complex. Though initially driven by self-interest—often internally mocking Shigeo's kindness while plotting to possess him—his actions gradually revealed a protective side. He warned Shigeo about deceptive situations, such as a fake love letter, and intervened to shield him from emotional trauma, searching for signs of struggle during a house fire and assuring Shigeo of his family's safety. He also aided Ritsu in awakening his psychic abilities and assisted in rescuing him from the Claw organization. Ekubo's abilities include possession, which unlocks 100% of a host's physical capabilities without exceeding their limits to prevent permanent damage, energy-based attacks like the Wraither Beam, crowd hypnosis, and consuming other spirits to regain strength. His role expanded during critical conflicts, like the battle against Mogami, where he temporarily possessed Shigeo's body to protect it and later entered a mental mindscape to restore Shigeo's memories. During this, he acknowledged Shigeo's growth and expressed concern for his well-being. His development culminated in the Divine Tree Arc, where he harnessed the tree's energy to achieve a golden, muscular "God" form and attempted to brainwash Japan into worshipping him. However, battling Shigeo revealed his true desire was not godhood but meaningful connection and friendship. Accepting this, he sacrificed himself to contain the Divine Tree's rampant growth, resulting in apparent disintegration. He later reappeared after Shigeo momentarily lost control of his powers, ultimately returning as a companion during Shigeo's part-time exorcism work. Throughout his journey, Ekubo evolved from a self-serving spirit to a loyal ally valuing hard-earned strength and humility, openly expressing admiration for Shigeo's character. His brash, humorous, and cunning nature persisted, yet his actions increasingly reflected a steadfast commitment to Shigeo's safety and personal growth, solidifying his role as a trusted figure within Shigeo's circle.