NOTE: For the Sunder build, the ultimate talent at level 20 is personal preference at times. Upgrading Sunder is useful for initiating teamfights, Nexus blades for sticking potential and the blink talent is nearly useless with this build but some players still prefer it.

However in almost every situation, you will want upgrade your Sunder because with this build you are a teamfighter.

Basically the difference with this build compared to almost every other Thrall build is that it is not a Windfury based build.

The build is made for teamfighting and has better wave clear than the Windfury build, which in contrast has more of an assassination based focus.

The only difference between the two builds shown is the ultimates, and the only reason you would take Earthquake over Sunder is when theres an Illidan on the enemy team, or some future equivalent in mobility and cancer.

First of all it's less countered by Illidan because you do not rely on Windfury and as all know, Illidan is FoTM right now.

Second people will be surprised at just how strong Chain Lightning spam can be and how strong your Windfury attack is regardless of not putting talents into it.

On top of this, your range is increased with this build, which adds kill potential. Teamfighting is also superior to the windfury build.

Earthquake counters Illidan teams because it limits his ridiculous mobility, use it to protect the squishies hes obviously going to go for in the back.

Thrall has never felt assassin'y.

Your 1v1 potential is still quite high just off of Thralls high base damage.

You can still single out squishies and destroy them nearly as fast as with a windfury build but now with the added bonus of having HUGE teamfight presence.

I'm sure you don't play Thrall like you do Zeratul anyway.