The Magister

The Magister is an upcoming solo boss that will be located in the Sophanem Slayer Dungeon. Gaining access to fighting the Magister will require a Key to the Crossing and level 115 Slayer. This will be boostable using items such as the Wilder pie. The Magister will count as a Soul Reaper task and will drop 5 new lore books.

On 6 June 2017, a teaser message for the boss appeared in-game, which was triggered by enough players interacting with the Sophanem Slayer Dungeon and Shifting Tombs:

Trivia

 * The Magister's name is Oreb, who was Nomad's old master.