I'm able to sit in one place and tank any uber bosses with this build.
The items that you need for this build mainly require stacking of all resist, max discipline, and critical chance.
Bola Shot(Thunder Ball) - I like to switch between Thunder Ball and Volatile Explosives in different fights. Thunder Ball when fighting uber bosses and Volatile Explosives when farming because bigger explosion means I'll have more life leech overall with more dps.
Vault(Trail of Cinders) - useful when getting out of situations such as being in middle of high damage aoe attacks. If used with Shadow Power(Gloom), you can get out of places while leeching life with full hp.
Elemental Arrow(Ball Lightning) - mainly used to charge up discipline. Since this attack zaps targets multiple times, with Night Stalker passive, you will regain discipline in no time.
Shadow Power(Gloom) - This skill should be active at all times because this skill is the main reason you will be able to tank through everything.
Preparation(Backup Plan) - Although with this build, you will have enough discipline to keep Shadow Power at all times, sometimes you won't be as lucky with critical chances.
Sentry(Guardian Turret) - this skill allows you to have 15% more damage reduction when you are in the turret bubble as well as giving you more dps from the turrets
Night Stalker - passive to have chance at regaining discipline when you critical hit.
Archery - just for extra dps
Perfectionist - 10% added to all your defenses with reduced discipline cost for your skills.