Arkyn of Law is a Lord of Law. He saved Corum's life and became his ally in the fight against the Sword Rulers. Arkyn was the former ruler of the Fifteen Planes, but when Chaos took over in the form of the Sword Rulers and their Mabden, Arkyn was defeated and cast into a diminished form, known as the Giant of Laahr. Corum's defeat of the Knight of the Swords restored him to his true form.
He became Corum's ally and helped him many times throughout his journey. He was instrumental in the defeat of the Queen of the Swords, Xiombarg.