Noblesse S01E08 - Frankenstein / First Contact

Since contact with Regis and Seira has been lost, Regis's grandfather, Gejutel, heads to Japan on Raskreia's orders. Once he arrives there, he unexpectedly runs into Frankenstein and Raizel. Who were the Frankenstein and Raizel that Gejutel knew in the past? Are their true identities finally about to be revealed?