Muradin has long been a consistently good hero throughout the years of HotS, not to mention a good example of a flexible talent tree. In recent times he has remained virtually unchanged until the last couple balance patches. Before these patches, you had a couple competitive ways to play: You could play a tankier-style via Dwarf Toss builds, or with other various tanky talents, or you could play a damage-style via Storm Bolt talents, and various other talents that allowed you to deal more damage. Neither were particularly that strong but they had their merits.
Given his tree, there was still a lot of improvement that could be made, but overall it was decent. So then comes the March 2nd balance patch, We see a nerf to his damage build and a buff to his tank build. Essentially both were doing pretty good. In competitive it was a toss-up, both saw extensive play which yielded similar results. With that in mind, the damage build overshadowed all other builds in Storm League. This was not because the talents were inherently too powerful, it was just a better fit in uncoordinated games a.k.a Storm League. The developers needed to take a comprehensive look at the hero to determine what needed to be changed, and they tunneled too hard on his damage-talent popularity. If you have a problem with talents that are more popular than the others in their tier but are themselves strong at best, and the hero is balanced with an average win-rate, you find out why the other talents are being picked less and you make adjustments/buffs to them to make them more popular instead of unnecessarily nerfing another playstyle.
As a result of this the damage build’s strength and popularity declined, but it was still a solid build. It saw a massive decline in competitive and a mild decline in Storm League, but the guillotine came down on June 15th when they released their balance patch. It was here where they decided to change Muradin’s baseline to a simple level unlock. This was a great change for his tree since Sledgehammer, though a damage talent, was often just picked even in tank build to get his baseline done quicker. However with the change, this aspect of the talent is now non-existent, and unfortunately most the reason it was even picked was for the faster baseline quest completion since the extra damage to non-heroes was usually an ineffective component unless paired with Perfect Storm.
Then they changed Perfect Storms Functionality:
"Quest: Basic Attacks against enemy Heroes increase Storm Bolt’s damage by .5."
"Quest: If an enemy Hero is killed within 3 seconds of being hit by a Storm Bolt, increase Storm Bolt’s damage by 10."
This was a devastating blow to his damage build, essentially needing 8 (or 10 if you consider the pre-March 2nd version) basic attacks instead of hitting 1 Storm Bolt to get the same amount of damage increase. The reason they gave was essentially that they didn’t want players sub-optimally using Storm Bolts for stacks. The problem I have with that is most of the time (at least in my personal experience) good players would constantly disrupt enemies in lanes of travel, on camp invades, or even drive-by them. All of which were used to slow the enemy team down and disrupt their cohesion and were especially effective for Muradin since he would also gain damage from this. So few bolts were wasted or used sub-optimally in this sense. Considering the cooldown reduction he gets after unlocking his baseline it is encouraged to use your bolts rather liberally aswell.
With all of that being said, it is much harder to get 8-10 basic attacks in than hitting a bolt, and it takes more time. With the way it is now, the damage you get is pretty irrelevant and it is just better to pick one of the others in the tier. With Sledgehammer having nothing but a meager non-heroes damage increase on an ability that won’t do much damage at all, it is pretty much irrelevant aswell. The damage-playstyle has become far weaker than tankier-playstyle to the point where you would question ever picking those damage talents.
So what I suggest is to revert Perfect Storm, and give Sledgehammer a 15% Storm Bolt range increase. This should bring back Muradin’s damage build so that all the players who enjoyed this playstyle can return to playing it, and for his build diversity to be restored.