Pros: Insane damage, single target and aoe. Mobs explode. and when i say explode, i mean disintegrate.
Cons. HORRIBLE close range damage. stairs are your worst enemy (grenades roll down them).
-Grenades, Tinkerer - great for hatred regen, especially with the +2 from grenadier.
-Cluster Arrow, Cluster bombs - this is your nuke. enemies will explode. HOWEVER - you MUST stand at a distance in order for the ball to drop directly on them. Also, don't shoot over walls, it does not explode on contact. You will probably only get 3 casts with a full hatred bar, so make them count.
-Caltraps, bait the trap - adds insult to injury for your damage.
-Smoke screen breathe deep - this is your survivability and aggro drop. you're gonna want the tank to take hits, not you. also use it to run away from mobs. breathe deep is chosen because cluster arrow is a HUGE drain on your hatred and you'll need all the regen you can get.
-Prep, battle scars. Who doesnt love a free heal? It heals for way more than a potion (12,000 if you have 20k hp). use this to regen your discipline and keep up smoke screen to stay at a safe distance.
-rain of vengeance, stampede. sometimes you'll become overburdened and/or surrounded. smoke screen, pop this, run away.
-grenadier - must have for this build
-vengence - you need all the hatred you can get
-archery - insult to injury on top of massive dps
I find it best to hold down shift when casting with the mouse. that way i can spam grenades in all directions as well as cluster arrow without accidentally moving out of my trap. I use this spec when clearing trash. If you encounter extra fast, telephoning mobs. this build is garbage. Opt for a freezing arrow, immobilizing trap build in that case.