Up to +5-20% Strength based on the charge time of your heavy attacks. Stacks 3 times.
+5-8% Strength for 4.5s on Kill. Stacks 5 times.
+4.25-5% Strength for every Enemy you Stagger. Stacks 5 times.
Weapons
Crucis Mk II Thunder Hammer
Locke Mk IIb Spearheard Boltgun
Feats
5 - I like extra toughness on kill
10 - Retribution is nice for attack speed ( Note I actually would recommend Punishment for stagger and uninterruptible )
15 - Benefits whole team passively
20 - Gives health when you really need it once until death procs
25 - Damage boost
30 - Extra utility or attack speed