This is my revision to the Ascension power Lightning Arc:

Stormwroth Revised:

Lightning Arc:
This power creates a number of electrical bolts equal to the WP Bonus of the Psyker.
To hit the Psyker must make an Challenging (+0) Invocation test to hit. One bolt will hit plus one per DoS. Unnatural Willpower will add to the number of hits if applicable. Each bolt deals 1d10+10 E damage with a Penetration of 3 and has the Shocking special quality.