When you dismiss him, he says he'll be at the King Crab Inn.
Minor Bug - Text update, please. I spent 10 minutes looking for him in the Inn and he's at the Hall of Heroes. I couldn't even see him until I (alt)+(`).
Did you dismiss him either the first time you entered the Hall of Heroes, or before that?
Once you officially unlock the Hall of Heroes (by speaking to the NPC there and returning by portal to the main section of the End of Time), any companions in the King Crab will be moved to the Hall of Heroes.
