The Necromancer's Path.

...which is already prohibited on it. You definitely have a mod installed that unlocks all heroes. No map can override its effect. In addition to Arantir, the player has access to 4 heroes: Naadir, Kaspar, Zoltan, and Ravenna. The remaining 4 are available for recruitment by Giovanni. The heroes from the campaigns and other factions are not available on the map.