This power functions continuously and does not require a Psychic test to use. The creature can attack in the Shooting phase using a focused blast of warp energy instead of a ranged bio-weapon. This counts as a weapon with the following characteristics. A standard roll to hit is needed for the creature to get the blast on target.
Rng: 24" Str: 5 AP: 3 Type: Assault 1 Blast
Alternatively the creature can opt to tap into the energies of the hive mind to unleash a more focused bolt. There is a risk of the coruscating power frying its brains, so to use the high powered bolt the creature must take a Psychic test. If the test is successful, the blast uses the following stats.
Rng: 18" Str: 10 AP: 2 Type: Assault 1
Errata — Chapter Approved: Codex: Tyranids Q&A (v2.0): Warp Blast costs 20 points as a Hive Tyrant's army-list option — where the "genomorphed"/custom-creature cost tables disagree with this, the army list figure is the one to use.