The Necron Death Ray are the closest thing the Crons have to a Laser weapon. Contrary to GW's lack of scientific wisdom, the Death Ray's lasers actually behave more like a proper laser should unlike the more iconic Lasgun. That is, it fires a white, blinding light of semi-invisible photons rather than the usual red pew pews you see in every Sci-Fi franchise ever.
A Death Ray is a ferocious Necron weapon most commonly found as the primary weapon for Doom Scythes. The Death Ray is aptly named and rightly feared, for there is seldom a warning before the weapon strikes, for any sound it makes is lost under the unearthly wailing of the Doom Scythe’s engines. A particularly alert foe might recognize the nimbus of energy building up around the focusing crystal, or the abrupt change in air pressure; but few recognize the significance in time. The nimbus pulses one final time and a beam of blinding white light bursts from the Doom Scythe’s underside, vaporizing infantry and tanks alike, leaving only charred and rutted terrain in its wake.
A single Doom Scythe can carve its way through an entire armored column so long as its Death Ray remains operational and a full squadron can reduce the sprawling spires of a hive city to fulminating slag in less than an hour. Mounted as part of an underslung turret on a Doom Scythe, a Death Ray fires a narrow beam of intense energy capable of passing through many enemy units and vehicles before the energy is dissipated, often vaporizing whole battle lines with a single shot and leaving nothing but a line of ruin in its wake.
Focused Death Ray
The Death Ray's much more dangerous cousin.
A Focused Death Ray is a ferocious Necron armament that is mounted as the primary weapon on a Sentry Pylon. The coruscating beams of force emitted by the Focused Death Ray are able to slice through entire ranks of enemy soldiers and whole columns of armored battle-tanks with contemptuous ease.
Utilizing an advanced focusing array, a Sentry Pylon is able to project its crackling ray over far greater distances than previously encountered versions of the Death Ray weapon, and with a destructive potential that is efficiently effective. When fired, the narrow beam of intense thermal energy fired by a Focused Death Ray will vaporize everything along its line of fire, and often passes through several enemy units before the energy finally dissipates; leaving nothing but a line of charred ruin in its wake.
But what the Focused Death Ray does best is its effectiveness against aircraft. The literal lightspeed attacks of the Focused Death Ray means that it does not really need to take account of wind conditions, the planet's curvature and estimated distance between target and weapon that plagues most races anti-air batteries.
It should be noted that the Focused Death Ray looks extremely similar to the regular Death Ray, rather, the larger power source from the Sentry Pylon makes the weapon far more potent than its lesser cousin.