The Norn Emissary is a comparatively recent horror to trouble the galaxy's defenders, an immense warrior organism that embodies the direct will of a Norn Queen, one of the mysterious progenitor-creatures from which a hive fleet's bioforms are ultimately grown. Standing taller even than a Hive Tyrant, it fuses raw physical might with formidable psychic power, and it is created for a single, chilling purpose.
An Emissary is an assassin. Before it is unleashed, its Norn Queen imbues it with the distilled psionic spoor of a chosen victim and whatever knowledge it will need to run that quarry down, and from that moment the beast is utterly fixated. It stalks gifted enemy commanders and prized captives with an eerie, gliding grace wholly at odds with its bulk, tearing through fortifications to reach a target the Hive Mind wishes silenced, or bearing a knowledgeable prisoner away for the fleet to unravel.
In battle the Emissary is as deadly at a distance as it is up close, lashing out with psychic tendrils that carry an array of warp-born torments, neural blasts and mind-searing lances of force that can boil the very thoughts from an enemy's skull. It is the Hive Mind reaching out with deliberate, surgical intent, no mindless engine of the swarm but a purposeful hunter dispatched to claim one specific life.