Up to 5-20% Strength based on the charge time of your heavy attacks. Stacks 3 times.
10-25% Rending vs Staggered Enemies.
1-4 Burn Stack(s) on Critical Hit to a maximum of 3-12 Stack(s).
Immune to Ranged Attacks for 0.6-1.2s on Weak Spot Hit.
*Inspired by Reginald's Berserker Psyker build + a comment left by the user @definitelynotadam under it.