Currently there are 5 unique monsters around that look like others that each carry one. And the quest for them have not been implemented yet. For more information there is a thread already about this in General game discussion.
I would make sure you get 1-3 levels of the skill fortitude and get plenty of AD and AC. The crazy Guy is part of the main quest dealing with Lodar's hideout which isn't finished yet either.
The forums have a lot of info on quests, character builds, and legendary/extraordinary items. I would suggest rummaging through the General Game Discussion topic and you will find out pretty much anything you need, evem quest spoilers if you wish to get help. Also mist quests have two paths and each path has their own perks/consequences. Good luck and I'm glad to see another forumer!