I was having some problems with Nightmare butcher, so I tried a few builds and by far, this one worked out best.
The Build: http://us.battle.net/d3/en/calculator/demon-hunter#aZdXVh!Yed!ZZbZbZ
Active Skills:
Left Mouse:
Hungering Arrow - Cinder Arrow: Your basic long range hatred builder.
Right Mouse:
Impale - Chemical Burn: The boss killer. This is your main attack, it costs a lot of hatred, but it also does a lot of damage, keep using it until your hatred is empty, then use hungering arrow to regain it while running away from the Butcher at all times, and watching out for the fire on the floor.
Vault - Tumble: Your main tool for staying away from the Butcher and out of the fire.
Smoke Screen - Lingering Fog: Your backup tool in case something goes wrong, gives you a few seconds to get to a good position without getting attacked. Also works well with Brooding which will restore your HP while you are cloaked.
Preperation - Battle Scars: This has two very important uses. First, if you run out of discipline and need to use Vault, you can recover it instantly with it. Also, it can heal you for a whopping 60% HP. Save it for if the Butcher pulls you to him, or you step into the fire on accident.
Companion - Bat Companion: Gives a much needed boost to your hatred regeneration so you can keep using Impale.
Passive Skills:
Steady Aim: Much needed damage.
Archery: Using a bow Archery really helps with damage. With a crossbow however, if your crit chance isn't high, I would go for another passive. You don't get sharpshooter until way later anyway.
Brooding: Important for staying alive. Works well with Smoke Screen.
