Bound by Blood
Using Blood Tap on a target with less than 50% health binds them to Hakkar for 3 seconds, forcing them to stay near him.
This has a 30 second cooldown.
Hakkari Devotee
For every enemy hero effected by Hemmorage restore 150 (+4% per level) health to nearby allied heroes.
Increase health restored to nearby heroes by 50 for each Blood stack.
Burning Flesh
Flay damage increased by 50 (+4% per level) if the target is disabled.
Hakkari Cult
Nearby allied heroes can be effected by Hemmorage, giving them the
Blood effect only. The amount of Blood stacks on allied heroes increases Hakkars spell power and movement speed by 10%.
As a troll intusiast I wanted to say my words early.
First of all, it's not very clear what's Hakkar's role in game. He is labeled as specialist but he got extremely low mobility and relies on debuffs and life stealing, what makes me think he plays more like a bruiser. In my opinion you should define what is his role when laning, Team fighting and holding objectives so you can make the tweaks to make him better on what you want him to do.
Second, the duration of abilities are too long. 6 seconds of silence as a base skill and after that 7 seconds of silencing from the heroic removes any chance of reacting to him. I'd suggest you to check this numbers and try to imagine how is to play him and how is to play against him, so you can balance it better :)
At last, I want to start this thing where people interested in troll content in HoTS joins and help each other, so I'll soon release some images and content to help people creating their own concepts and develop their ideas. I'd like to send you this link here so you can use it, if you want to, and join the movement: https://i.imgur.com/JITnpyV.jpg it's very generic so many people can use but this is a first release for you since I got this idea when I saw your post.
My intention for Hakkar was to actually have him be a Tank (bruiser), but the more and more I went on with the hero the more I found him onto be a mix between a specialist (Able to 1v1, secure lanes etc) and tank, mitigate damage for his team so in a way he is much more like Medivh; Support but able to hold lanes.
So basically getting Blood stacks is supposed to be hard (with basic attacking) while using Hemmorage is a far easier way to get Blood. I do agree the duration and numbers could use some tweaking which I'll get to right away :D