A Different Way to Fix Rengar

A lot of people are suggesting some different ways to change Rengar without destroying his kit, and I think I have a decent idea. His Bonetooth Necklace should require two assists for a trophy. This way he can't just bum assists off a few kills if he's not doing well and immediately hit a power spike. He should be rewarded for doing his own work and getting his own trophies. I get tired of a shut down rengar coming back after throwing an e and hitting w in a team fight. I think there are other changes that should be implemented, but this is just an idea.

What do you guys think?