Alright Shiv bros, after coming back to the game I was disappointed in all the massive amount of nerfs he's gotten and thought he was unplayable but after trying some more and experimenting, I really think this is the build.

Radiant regen+Healing tempo is really the key here. Mystic/Radiant is good for general sustain, giving you regen any time you stick somebody and the buff will persist 5+ seconds after your knives stop bleeding AND it stacks making it amazing in team fights, mystic shot can also trigger the regen buff too.
Radiant regen gives you a heal and gives you a small move speed boost any time you cast an ability BUT if you combine this with healing tempo it triggers it's effect, which collectively gives you a heal, 40% fire rate, and +3.5 move speed. Healbane is also a great combo here, giving you a massive HP boost any time you execute someone and then buffing you after.

Most games I end up grabbing debuff remover too, it's just too good considering how many debuffs are in the game now. If I REALLY need to be tanky, juggernaut is amazing as well.