Core skills:
Multishot - Suppression Fire
Preparation - Punishment
Infinite high AOE damage out put against large amount of mobs.

Secondary offensive skill:
Impale - Chemical Burn (Impact and Grievous Wounds are nice too)
Highest damage/cost effect for single target, effective against Boss/Elite.

Other skills:
Caltrops - Bait the Trap
Good for both offensive and defensive.

Mark of Death - Valley of Death
Amlify damage for Multishot.

The last skill:
Vault/Smoke Grenade for survival
Companion for GF
Shadow Power for life leech
not sure which one to use at this moment.

Weapon of choice: Crossbow, high damage, low speed.
the build doesnt rely on any conventional Hatred generating skills, thus attack speed is not important. Damage is the only concern.

please comment. thanks!