After retirement, he spent his time tutoring the next generation of mages. He lived in an abandoned tower in exchange for a donation to the duchy's treasure. He became famous from Icewind Dale to Calimshan as a very patient teacher of the arcane arts. Delfen also helped the local militia in all magical matters.
Delfen was presumed dead around 1385 DR. However, in 1485 DR, he returned to the town, not a day older, and reclaimed possession of his tower. He was Delfen for certain, but never spoke about what had happened to him in his century's absence.