Clay Cliff Fortran is candidate number 89 at the Goddess Operation Academy (G.O.A.). Aged 15, he stands 159 cm tall and weighs 53 kg. He possesses the EO blood type necessary for piloting eligibility. His physical appearance includes gray eyes, brown hair cut to ear length, and he wears glasses.

Unlike most candidates, Clay did not join the G.O.A. primarily to become a pilot. His motivation is strictly academic and research-driven, focused on studying and theorizing about the Ingrid mecha and related systems. Known throughout the academy as the "class brain," he exhibits broad intellectual curiosity, frequently punctuating his discoveries with the phrase "Very interesting" when engaging with technical or theoretical concepts. His designated Repairer, Saki Mimori, maintains his practice Ingrid unit and mitigates neural feedback during operations.

Clay is documented as gradually developing EX abilities, superhuman powers that interface with the Ingrids' control systems. His background prior to enrolling at the G.O.A., including family history or upbringing, remains unrecorded. Information exists solely for his core depiction within the manga and anime adaptations.