I wrote this in a Google Doc since it's much more convenient.
https://docs.google.com/document/d/1qiEwoxxPavXDi1REfHi_HWXxjOvXv_ewxxo3giegnoA/edit?usp=sharing
Art was NOT made by me. Feedback would be greatly appreciated!
Real great concept, I like the idea of a more systematic assassin playstyle. Excellent ideas across the board with Contract and Abduct (both the active and the passive), but I do have a few questions.
Is Bistir Ranged or Melee? This affects how his assassinations work and also how he uses Phantom + Blink of an Eye.
About Phantom, why does it scale with AP? What kind of damage does it do? Why is the invisibility so short? I'd like to know more about your reasoning behind this ability.
I'll be honest, it kind of seems like you added all the Final Destination synergies because you didn't know how to synergize the entire kit cohesively. Nevertheless, they're sort of interesting on their own, and I can see the potential combos. Again, it would help if you wrote down your reasoning for the individual abilities.
That's all the bad things I can say about this concept, and believe me, I tried! Excellent work!
Reviewer, away! 
