Need help remembering a book series and I know the TD sleuths can come through.

I have spent an hour on the internet trying to find this book series. Here are the things I remember.

Genre was fantasy.
I read them in the ‘80’s.
Premise was something about a fog/mist/darkness of some kind moving across the land and in it/behind it was army of orcs/ogres etc.
Their were typical characters- elves, dwarves, halflings.
Their was one human character I believe named Dax or Daks. He was described as a weapons expert almost like a ninja. In the last book he had one on one battle with a creature that in my memory was like a giant red ape.

Any ideas??