The swamp and the mountains had a very beautiful demon baby.

I consider myself pretty good at this game and have(had) high skill levels, but the Mistlands has kicked my butt over the last couple weeks. Prepare to die a lot but have fun with it.

Edit: And to answer your question, there are lots of nice new weapons and items. But I highly recommend you go through the Plains and get experience surviving there before even attempting to enter the mist! :)