Dajik is some form of shaman, with a small heal known as Mend that can range anywhere from 500 - 900 and everything in between, it would seem however that he will only attempt to heal you once you drop bellow a certain unknown percentage of health that could be perceived as near half. He Will heal you until he is either out of mana or until you are somewhere near 90% healed. He will also engage in melee combat with your enemies prompted either by their attack or yours. Though his exact skills are unknown.
He is the second companion you obtain from the Frenzyheart and will soon be replaced upon completion of that portion of quests, but can be reacquired through speaking with High-Shaman Rakjak. He is easily one of the most useful companions to keep and possibly the only reason to chose the side of the Frenzyheart later on in the chain in the quest A Hero's Burden where the player may choose to align himself with either the Oracles or the Frenzyheart Tribe.