UESP
Telvon does not exist in the original game (except for a seemingly unassociated smith). He is only mentioned in a note which can be found on the door of Indoranyon.
Note
Modded
Telvon is said to have disappeared after trying to enter Indoranyon.1
Quote
I knew you must have found my note to Telvon. I have no idea where he is. He was a bull-headed man and I fear that he may have entered the ruins of Indoranyon despite my warning.
— Hairan Mannanalit (dialogue)1