Arkanis Gath

A human male Shadowthief which will oneshot your characters if you attack the Shadowthieves prior to having been to the Underdark (if siding with the thieves) or prior to attacking them on Bodhi's orders (pre-Underdark) if you sided with her. He only serves the purpose of protecting the main plot and only appears if you attack the thieves. If you attack the thieves on Bodhi's orders or after having come back from the Underdark, he will appear shortly, but won't attack.