Maria Tengai, younger sister to Tomisaburou Tengai and granddaughter of a precognitive grandfather, traveled Tokyo with her family. They relied on the grandfather's psychic powers for street predictions until the 13 Apostles destroyed their village, killing their parents and forging a shared vendetta with Shinichi Kuruma against the Apostles.

Maria's significant psychic abilities marked her as a key target for the Apostles, who deemed her powers essential for ushering in their new world order. Her character carries symbolic links to the biblical Virgin Mary within the narrative.

She dies in Shinichi Kuruma's arms during his confrontation with the Apostles. This death profoundly impacts Shinichi, directly catalyzing the "Great Destruction"—a series of devastating earthquakes that ravaged Shinjuku. It becomes a core motivator for Shinichi's ongoing hunt for the Apostles.

In the alternate-universe sequel *Beast Fighter: The Apocalypse*, Maria's legacy influences character dynamics. Tomisaburou Tengai references her death when warning Shinichi about the dangers of his growing connection to Ayaka Sanders, drawing a parallel to the past tragedy. Shinichi absorbs Maria's corpse into his own body, a visceral act granting him extended life to sustain his crusade against the Apostles.