*KEEP IN MIND! This build is from my personal experience and is in no way meant to be a pro build, nor am I in any way and expert!*
Tier 1: Corruption allows for very easy cannon/fortress destruction. If you are soloing a lane with minions, it makes it easy to disable cannons and fortresses. Yes, you standard shot disable the buildings, but that only lasts for 1 second unless you choose Paralysis. All the other option haven't personally been super effective.
Tier 2: Overflowing Quiver allows room for a little extra damage to minions, mercenaries and/or heroes if your quiver is full.
Tier 3: Life Drain allows you to heal and has personally gotten me out of some sticky situations. It's not much health but it's helpful, especially if your advancing far in a lane and cant turn back for a healing fountain or hearth.
Tier 4: Wailing Arrow This one is situational and opinionated, but more times than not you're not really going to use Possession as it is only good for getting larger minions and mercenaries. This ability allows you to silence enemies, which takes away enemies heroes ability to use their abilities.
Tier 5: Evasive Fire Is good for getting out of situations in which you are surrounded. While dealing damage, it also allows quick evasion. combined with the ability Haunting Wave it makes for an easy escape.
Tier 6: Cold Embrace makes enemy heroes take more damage, which is helpful for yourself and your allies in an assault situation. It does lower it's range, but that shouldn't be a huge problem.
Tier 7: Deafening Blast Makes enemies take 50% more damage than the original and they are silenced for 50% longer. It's really the only choice for the final tier. Bolt of the Storm is unnecessary because of your other two abilities and Fury of the Storm is in a sense a less powerful version of Shadow Dagger with your talent choices.
Thank you for your time! Feel free to build upon this build or give suggestions as to what I can refine to make it better. Remember, I'm not a pro, and this is just the build I had the best games with. I'm sure something will come along that's much better, but this is just my opinion.