Just put a single point in this skill because it is not you main damaging ability, don’t need the tier bonus, and debuffs are fix on any level.
Heavy Lifting (15 Skill Points)
The first passive skill that you should max since your basic attack is your primary source of damage.
The attack speed bonus lets you deal more damage per second and helps proc Supercharge.
The bonus chance to stun disables target enemy and helps proc Coup de Grace.
Supercharge (15 Skill Points)
This is the second passive skill that you should max. Even at lower skill level, the passive procs a lot.
Becoming supercharged boost your damage and quickly fills up your charge bar. Ember Hammer and Forcefield will benefit most from this passive.
Coup de Grace (15 Skill Points)
At earlier levels, you won’t appreciate this skill since there are few available stun chance. Just put a single point early game and max this skill last.
You will experience its true power on your higher levels where lots of stun chance is available from skills to equipment.