Koftik is a human that serves as a guide through the Underground Pass during the quest. He teaches players how to make fire arrows to enter the pass and also appears throughout the dungeon. During the quest, he will give the player some food at most of his locations in the dungeon because "it is a dangerous area". However if you've recently claimed some food from him, you will have to wait for some time for more.
Throughout the quest, he slowly loses his mind to Iban's influence. But once Iban is slain at the end of the quest, he regains his sanity. After starting the Regicide quest, he can also be found in the Well of Voyage in the Underground Pass.