This Boss is very capable of wiping out your entire party if you're not careful or are clumped up. Be sure to interrupt him if possible; Broadhead Arrow, Maelstrom or Power Block are viable options. It is also possible to solo this boss with a sliver perma, which can make things a whole lot easier.
Bug! This boss will not attack back when shot from a distance with a Longbow or Flatbow. He can easily be killed that way by any profession, although it will take a while without high marksmanship.
The name Lok may be a reference to Loki, the Norse god of mischief and firelight.