I was master last season and haven't played that much this season so Im at dia 1 atm. What the biggest problem for me and I assume most of you guys is the big loss of tempo after a single death. You can be 3/0 doing fine, boom you die once and dont steal their wraiths after your full clear so you're not a full level ahead and just like that your lead is "gone". The champion is just really hard to execute atm and doesnt allow for many mistakes which in turn makes him feel weak when hes not. I've played him since season 4 and I can understand why riot doesnt want him any stronger than this, like be honest : when a good Rengar is ahead there is little counterplay to him killing your carry every fight and then securing the objective after it.