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Tal'darim Executor Nyon deployed aboard the ship to the Sigma Quadrant Worldship, an abandoned xel'naga worldship, during the Second Great War. The worldship was being attacked by Raynor's Raiders to secure a component to a xel'naga device under Tal'darim protection.
The terrans destroyed the mothership, taking Nyon down with it.
The Raiders made off with the component.
The mothership creates a Vortex that absorbs nearby units, allied and enemy alike, into it for the duration. The mothership will not be absorbed. When the Vortex ends, all affected units reappear around its location.
Units leaving the Mothership's Vortex are un-targetable and immune to damage for 1.5 seconds.
The area of effect is 2.5.
This ability is removed in Heart of the Swarm.
In addition, the mothership projects an aura similar to that of a pylon or deployed warp prism and will summon units to its location using the warp-in animation. This ability does not appear on the game unit's UI board.
The Tal'darim Mothership is simply referred to as "mothership" in "Maw of the Void" and has the standard portrait. The name is derived from the map editor.
It is possible to defeat the mission without destroying the Tal'darim Mothership, but it requires a non-standard approach. If so, the executor's death quote is not given.