A non-killable NPC that plays two roles in the Runnyeye story. One, to inform you hes one of the good guys and wants to help you out, and two, as previously stated, to teleport you out of the "Big Eye" room which has no other exit.
A guildmate and I entered the Chamber of Rulgax, slew him, looted the piddly chest and found the NPC Duke Zoryll on other side of Chamber. The Duke asked if we wanted our reward for killing Rulgax and he teleported us back to the entrance of RE with nothing. Might be a bug.