Professor Claude Epstein (クロード・エプスタイン博士) is the historical inventor and official founder of orbal technology, which utilises devices that operate by drawing orbal energy from septium. Epstein left various prophecies that have come to pass in the games.
Professor Epstein passed away in S.1154 with no known children by blood. His adopted daughter, Lillia Epstein, secretly went into hiding as Lillia Claudel without contacting Professor Epstein's three leading disciples for the rest of her life.
One year after his death, the Epstein Foundation was established in Leman, the birthplace of Professor Epstein. It was founded by his leading disciplines: Albert Russell of Liberl, G. Schmidt of Erebonia, and L. Hamilton of Calvard. The foundation was dedicated to continuing Epstein's work.
It is possible that F. Novartis is related to Epstein or his foundation in some way given how he has the same naming convention that Epstein and his disciples use.
- In Trails of Cold Steel III, it was revealed in the side quest with the Eternal Kandelaar that Professor Epstein was one of the few people that knew how Artifacts could work.
- Based on comments from Campanella and Mariabell Crois in Trails of Cold Steel IV, Professor Epstein was also one of the few people that knew about The Beyond.