Vanish. Used to be a "Duh" choice for ass/flee assassins. Now it's a "Duh" choice in the sense that there are very few situations where it's actually the best option.

If the goal of the nerfing was to make it risky to assassinate, why not just make it impossible (or work crappily) for some duration after a failed assassination?

This would address the issue of riskless-assassination without making vanish {mostly} useless.