Iogar can be first encountered in the Moonrise Towers barracks situated west of the hall and throne room, where he is resting with Kimmeral and an ogre named Mig. Under the belief that the party lead is a True Soul, Iogar will recommend them to find lodgings in the war camp west of Reithwin, due to the ogre's presence.
Defending Moonrise Towers
If the Nightsong is freed and the Harpers launch their assault on Moonrise Towers, Iogar will be part of the remaining forces defending Moonrise Towers, and can be encountered in the ground floor hall standing right behind Disciple Z'rell.