The Mists
The mursaat slip beneath the skin of the world
Refusing to surrender their magic into the Bloodstone after their allies' desertion, the mursaat use their shadowcraft to phase out of Tyria into a shadowed pocket between the world and the Mists, escaping the Elder Dragons.
Known as the Unseen Ones for their ability to cloak themselves from view, the mursaat wielded a magic called shadowcraft that let them slip beneath the skin of the world and phase between Tyria and the Mists. After the failed assault on Zhaitan and the other elder races' refusal to fight, the embittered mursaat would not give their magic into the Bloodstone.
Instead they shifted themselves out of phase with Tyria, into a shadowed pocket of existence, as a way to hide from the Elder Dragons. This withdrawal both spared them the dragons' hunger and deepened the rift with the Seers — a rift that would soon erupt into open war between the two former allies.