This is what I use on psyker^. Requires some specific blessings but
Voidstrike most of the time, duelling sword for defense and mobility or when high peril in a horde.
Blitz is mainly for the innate chance to proc when using staff and melee but I use it on far away fast moving targets where void would be hard to hit or on bulwarks or bosses when at high peril to do some damage before moving back to void strike.
Also brain rupture counts as a headshot for getting those guaranteed crit stacks.