Rune of Transfer in Nyzul Isle Investigation The Runic Disc is a key item used to record data for the Nyzul Isle Investigation Assault. Upon successfully completing the Assault and exiting, any progress is saved to the Runic Disc. If the Assault completed is a multiple of 5 (or greater), the information saved to the Runic Disc will allow to start the Assault mission at a higher floor. (Once you complete floor 5, you can start on floor 6; once you complete floor 10, you can start on floor 11, etc.) Starting from a floor other than floor 1 does cost Nyzul Isle Tokens.