TEXT: SHROUDWEAVER WAR CELL
  POINTS: 200 + MODELS
  A Necron onslaught begins in silence and terror. It is rare for a Necron
  Lord to reveal his intent in an obvious fashion, for an enemy assailed
  unawares is an enemy already beaten. So it is that an initial strike will
  often be carried out under cover of darkness, when most living beings
  are at their lowest ebb and vulnerable to the tactics of terror. Darkness
  does not always coincide with Necron plans, and, on these occasions,
  the Necron Lord will have to create his own darkness.
  A Harbinger of Night devours light over a considerable distance,
  reducing blazing sunshine to a murky twilight, and overcast grey skies
  to abyssal darkness. Few living creatures can remain defiant before the
  Harbinger of Night’s approach, for its power over the natural order of
  things awakens the deepest of primeval fears. Shielded by darkness
  and heralded with terror, the Necron harvest begins. When the skies
  clear once more, the battle is over.
  FORMATION: 
  1 Necron Lord (Harbinger of Night)
  3+ Necron Warrior units
  3+ Immortal units
  0-3 Monoliths
  SPECIAL RULES:
  Strike Force: Each unit in a Shroudweaver War Cell must be deployed
  within 6" of another unit in the formation. If coming on from reserve,
  they must enter the table within 6" of the point entered by another unit
  from the Shroudweaver War Cell.
  Unnatural Darkness: Enemies wishing to shoot at models belonging to
  the Shroudweaver War Cell that are within 12" of the Harbinger of Night
  must do so as if the the Night Fighting rules were in effect.
  Onset of Terror: At the start of the Shroudweaver War Cell’s Shooting
  phase, all enemy units within 12" of the Harbinger of Night must
  immediately test as if they had suffered 25% casualties, with a -1 modifier
  to their Leadership value.
  Out of the Darkness: The Shroudweaver War Cell grants your side the
  Ambush strategic asset.
  NECRON LORD 
  HARBINGER OF NIGHT
  NECRON WARRIORS
  NECRON WARRIORS
  NECRON WARRIORS
  IMMORTAL WARRIORS
  IMMORTAL WARRIORS
  IMMORTAL WARRIORS
  
SOURCE: textdata/thevault/Warhammer/40k/1st-8th Editions (Prior)/5th Edition (2008)/Apocalypse Datasheets/40k 5e - Necron - Shroudweaver.pdf