Mern is the leader of the scouts-soldiers of Blackmyre, his role giving his the title of Ranger of the Myre.
He is close friends with the current Lord of Blackmyre, Tergon.
In 374AC, during a scouting party, Adrak, leader of the Blackmyres, and his party, was targeted by Frey soldiers. Opting to flee into the swamps rather than fight, they retreated hastily, stumbling into a loch filled with lizard-lions. The only survivors of the incident were Tergon and Mern.
After the long and challenging journey back to Blackmyre, Tergon found himself raised to the title of Phantom of the Myre, whereas Mern himself was given the role of governing the soldiers of Blackmyre, garnering him the title of Ranger of the Myre.