Endurph serves as an Exif cardinal and lieutenant general aboard the United Earth emigrant ship Aratrum. A high-ranking Central Committee member, he participates in strategic planning after humanity's catastrophic defeat by Godzilla Earth. He specifically requests calculations on Godzilla Earth's atomic breath range, determining it could strike the Aratrum in orbit. Endurph pushes to search for survivors rather than immediate withdrawal, leading to a compromise deploying reconnaissance drones for 48 hours. He observes the return of a landing craft carrying Marco Ghione and two soldiers when survivors are detected.

Aboard the Aratrum, Endurph conducts religious sermons for passengers, preaching about vanquishing Godzilla and referencing a "promised day" when their god would descend. He frames the conflict theologically, emphasizing divine intervention. His role expands when he collaborates telepathically with fellow Exif Metphies to initiate rituals summoning their deity, Ghidorah. During the summoning, Endurph leads chanting prayers that successfully beckon the entity. Transfixed, he witnesses Ghidorah destroy the Aratrum and perishes engulfed in flames while laughing maniacally, a stark contrast to his typically reserved demeanor.

As an Exif, Endurph outwardly displays compassion and support for human survival, masking his species' true nihilistic motives. The Exif manipulate events to enable Ghidorah's arrival, viewing planetary destruction as spiritual transcendence. Endurph leverages his religious authority and military position for this agenda, utilizing technology like Gematron calculation under the pretense of aiding human strategy. His actions consistently align with Exif doctrine, which seeks to convert civilizations before sacrificing them to Ghidorah.