Riot about rengar - "Can't fix the sheen bug."
Riot Employer - Rengar Update: "Can't fix the sheen bug. Spent several hours, but really strange spaghetti interactions going on here."
About 1-2 years ago, before ap Rengar got guted, he was able to proc sheen and take down towers within several hits. I'm 100 % AGAINST such a radicilous thing, but being unable to use of certain item passive wich is not intended, should be taken as serious as any other non-intended in-game interaction and fixed without making Champion Broken.
A short suggestion below is only a SUGGESTION and it could not be the best one, but I'm aware to any critism or different thoughts.
Give Rengar back sheen proc.
Remove extra demage to towers.
Re-adjust scalings (lower if needed) - depends on the extra burst he would get from sheen.
**This change would probably make Trinity force a core item on Rengar, giving him stats he need (except mana), potentialy making him healther - delaying hes power spike by more