I believe Earthquake is on the verge of being a really good skill. There are several ways to build it where the damage is satisfying and matches the cost of the skill. The stun and the frenzy and haste nodes make for solid support options. But EQ has a very big problem.
EQ has a really large windup before the attack is completed. On top of this, it generally must be used close enough to enemies that getting hit is a normal occurrence. Because the player can get hit during the animation, they can also get stunned, and when they get stunned it cancels the attack. EQ is already a high risk/high reward playstyle with the large windup and mana cost, but because the player can also get stunned out of the attack, it makes the gameplay feel bad and also causes EQ to be detrimental to take over other options where the risk of being stunned is lower, and the attack is in far less danger of being canceled because it’s faster.
I propose that EQ receives the same effect as Warpath. EQ should have stun immunity during the animation that lasts until the attack is completed. Players should still be able to take damage during the animation, which maintains the high risk/reward playstyle, but taking the risk of stun out of the equation will make EQ gameplay feel way smoother and make using it less punishing in comparison to alternative options.