Up to 5-20% Strength based on the charge time of your heavy attacks. Stacks 3 times.
Recover 15-24% toughness when hitting an enemy with a heavy attack, based on charge time.
5-8% Strength every 0.4 seconds while aiming, stacking 5 times. Discharges all stacks upon firing.
20-35% Toughness on Elite Kill.