Koftik is an agent of King Lathas who features heavily in the Underground Pass quest.
In the quest, he is a guide through the pass, teaching people how to make fire arrows to lower a bridge, for example.
When spoken to in most of his locations he will provide the player with some food because "it is a dangerous area." You may have to wait for some time before he will give food again if you've already taken some.
During the quest, he slowly starts to lose his mind due to Iban's influence and started the process to deteriorate into a Half-soulless. However this doesn't happen, once Iban is destroyed he regains his sanity and can be found in the room of the Well of Voyage, as well as his other designated areas in the pass throughout the quest.