I have been playing Valla since the Alpha, and she is by far my favorite character to play with. I have seen lots of different Valla builds. I have created tons of in game Valla builds. But after months of playing and hours of games this is the best build I have made for all around competitive play. Valla is not great on her own, unless you go this route. As fast as she is and with her abilities I see no reason why you would not make her a lane clearing, Hero destroying wrecking crew, and this is the build that does all that. once you get Vampiric at level she is almost unstoppable. I would lane her against any Tank at that level with Vampiric. Level 7 was the trickiest spot for picking a talent. But given her ability to already be fast we want to push that an give her the ability to hunt down injured heros and finish them off, heroes you probably injured and are now trying desperately to get away. Strafe is the best for this build, and is generally good for teamfights. frost shot paired with executioner is a game changing combo late game, and provides quick clears or provides that extra damage vs heroes. the final Talent will allow Valla to remain healed up at all times keeping you in the fight to pick off as many enemy heroes as you please. She is fast, She is deadly, She is Valla. Go have some fun and let me know how this build works for you.