This is my first attempt at writing a guide so be gentle ;)

The following guide is my the build for Thrall that I have found the most success with. I hope you find it useful.

The build is focused on burst.

If you like the guide or even find it mediocre, please up vote :P

Tier 1 Wind Shear

For this build Wind Shear is a must. In fact, for most builds it should be the go to.

Tier 2 Envenom

A great ability for bursting. It's incredibly satisfying to throw this on someone as they turn to run only to die from poison.

Tier 3 Battle Momentum

This talent is superb here. Paired with Wind Shear you drop your Windfury cool down to roughly 4.5 second after using it. It's amazing.

Tier 4 Sundering

This talent is a must for this build. Earthquake really has no place as the goal for this build is burst.

Tier 5 Grace Of Air

An excellent ability. Quicker 5 stacks of Frostwolf Resilience means you can stay in the fight that much longer.

Tier 6 Tempest Fury

The burst power is strong with this one. Did I mention this is a burst build?

Tier 7 Bolt of the Storm

Thrall lacks escapability and this talent will save your ***. Trust me :)

My rotation is usually:
Windfury > Chain Lightning > Envenom

I say usually because it can depend. At times I will open with Chain Lightning because I can get it off before my first attack with Wind Fury hits. Or at times I open with Envenom because they are at low health already. I will use Feral Spirit right after envenom in the above rotation if it will kill them. If it will not, then I wait for them to turn and escape, landing it to stop them and catch and kill or use Sundering. I will also use Feral Spirit to initiate a ranged who is smart enough to run when they see me coming ;) It's a judgement call.

Thrall is a great hero. With this build I consistently hit top Hero Damage. Not only that, during mid to late game I can solo boss camps losing roughly 10% of my health (not that you should be doing this when it's time to fight as a team).

With most of the other melee assassins, during a team fight you get in and get out. Thrall can stand toe to toe a bit longer in team fights. This is due to his trait Frostwolf Resilience and the rate at which you can stack it with this build. But you still need to pay attention and bolt out when needed. Always be in position to do this as Thrall's only escape is Windfury (and Bolt of the Storm if you take it at 20).

This guide is a work in progress and will be updated as necessary.

Follow me on twitter at twitter.com/c0rpsey
and on twitch at twitch.tv/c0rpsey