The Void Ray is a Protoss air unit new to Starcraft 2. It's attack does more damage the longer it is locked onto a single target, making it most effective against powerful units. The Void Ray can move while it attacks, including moving closer to the unit it is currently attacking. It is not currently known how the player controls this.
A void ray is a ship virtually built around a single gigantic power source: the prismatic core. This device seethes with energy drawn from two realms: the Void, which is truly understood only by the dark templar, and the psionic matrix, which underpins the technologies of the Aiur protoss. In combination these two energies form a self-sustaining reaction of terrifying potential.
Normally the prismatic core is held in check by an arrangement of flux field projectors. When a void ray locks on to a target, the projector arms smoothly part like the petals of a flower. A complex array of warp lenses and phase-crystals works to focus the energies of the prismatic core into a ravening beam of destruction.
As the prismatic beam is held on the target, more of the focusing array becomes aligned, and up to three individual power streams combine together. Over a few seconds the beam's intensity and power grow exponentially. Few enemies can withstand the awful power of the prismatic beam for long: even large and heavily armored targets like buildings or battlecruisers are incinerated in moments.
Early in development, the Void Ray was known as the Warp Ray and did not have the appearance of a dark templar ship.