Valla is one of the most Effective Damage Dealers in Heroes of the Storm, with multiple styles of releasing it, either you like spamming abilities, or constantly Auto-Attacking, or the targeting of specific abilities that do tons of damage while also keeping her alive. Hatred is Valla's Passive which gives her increased Move-Speed and Auto-Attack damage, many talents also add effectiveness to Hatred.

Build #1 - Probably the most difficult of all the builds that I use but also has high potential for damage and Carry Potential. This build focuses on constantly attacking to keep your hatred high which not only will increase your damage, and movement but will also make your Life-Steal increase drastically. The Main drawback to this build is that the initial quest has a Loan on it, so dying will decrease your attack speed which is crucial early game. But if you can survive until late game this build will put great damage and Life-Steal to keep you alive.

Build #2 - Just like the name suggests it mainly uses Multi-Shot to deal damage, you will still end up casting your other skills but your main mana focus should be on using the W and saving your E for escapes. The Q in this build mainly focuses on clearing jungle monsters and also can be used for extra Life-Steal.

Build #3 - Not the most popular of the builds but does provide extra value in its safety and ability to clear not only waves but also the Jungle Monsters. You can solo most camps with this build, with maybe boss as an exception (But Still Doable) The Level 20 Skill that gives you extra Vaults also will increase survivability but also refresh your Hungering Arrow for massive damage and Life-Steal Spam.

I find with Valla that most of the choices are focused into whichever build you decide to go. But the Ultimate can be a spot for debate with her. Strafe is probably the easier to use and safer Ultimate it also doesn't allow her to attack during it which then means your Hatred will decrease. If you go Rain of Vengeance this will still allow you to attack and will also stuns your enemies which can allow you time to unleash damage on to your enemy. I usually choose strafe if I am going a Multi-Shot Build but Rain of Vengeance is the ultimate that I find most effective.