Could we have some discussion on changes to *unhealthy* or *weak* Assassins to make them viable.

I'l start the ball rolling here, I would like to talk about Kha'Zix. As a player who started playing Kha, back when he was a strong mid-laner, I've become quite disappointed with where my bug has ended up. Sitting at an average of around 46-48% win rate (lolking statistics) he is quite weak at the moment. Nutty a kha'zix main made a post about this on reddit (link here https://www.reddit.com/r/leagueoflegends/comments/3z7nl8/nutty_mastier_tier_khazix_otp_thoughts_on_khas/) and I think the best suggestion is about marking isolated targets automatically, and by mark I mean in a Nidalee kind of way rather than his current system. This mark would enhance Kha's abilities on that champ in some way (maybe the old Q % missing health and W applying his passive for example) and would be applied in a longer radius if Kha had vision of the target and in a (much) smaller radius If he didn't. This would not only restore Kha's identity as a solo predator, but would also allow Kha to deal more damage than a marshmallow to targets who were isolated then grouped as the mark would last 3-6 seconds (depending on balancing) giving him some impact throughout the game as well as having a much more interactive gameplay.

TL:DR Post about how to improve poor assassins and comment on other's ideas to help them improve. Good starts would be Akali, maybe Rengar and others.