You are about 40% done, or so.
Finishing off Maxos temple opened the way to a teleporter that will bring you to Sentinel Island. Your first encounter there you can mindread to go up a level, so the higher level you are (I made it to level 18 in the fjords) the more of an experience bonus that will be. You don't need to get to a high level, but it would be better if you got to a new level before entering, to get a full level bonus.
