I play a lot of games with rengar and get rekt a lot of time. My problem is that i can't carry with rengar bcs i don't have resistence or enough dmg to kill the enemy's carry before their CC reach me. Finnaly i find a build who let me carry a lot of games. Hope u will enjoy this short guide and excuse my language.I don't speak so well english.

FIRST OF ALL THIS GUIDE IS NOT A COMPLETE GUIDE FOR RENGAR . THIS IS JUST FOR RENGAR PLAYERS WHO ALREADY KNOW HOW TO PLAY HIM BUT THEY ARE UNABLE TO CARRY THE GAME BCS RENGAR IS DELETED EVERY TIME FOR TEAMFIGHT.
My guide steps:
1. you can choose another RUNES if u have armour penetretation or atack speed, but u should have the armour and mr runes(will help u a lot).
2. U must do exactry my masteries . Believe me , this masteries are the best.
3.When u begin the game start with GOLENS(SMITE)>BIRDS>RED BUFF(SMITE)>CRAB(U WILL GET SOME HP BACK)>BLUE BUFF or after crab u can put a ward on enemy blue or red (depends on enemy jungler) and make FIRST BLOOD. After that u must start to gank with full stacks on the passive>land bolla>get feed.
4.In teamfight u must wait until the team start the fight . When u see their carry have their hp lowered or u can kill him before their team catch u , atack them. A0fter that u can help your team clean the rest . Late game with my full build ,after u destroy their carry , there are no reason to fear about . The tanks dont have enough dmg to hurt u .At least if u
5. JUST DO THAT BUILD. DON'T CHANGE ANY ITEM . IT'S A CORE BUILD.The only item u can change its dead's man plate. If enemy team is more ap get spirit visage.
6. It's my first build so be kind and don't flame . If u wanna say something,say it after u try my build.
7. THANKS FOR READING GUYS!!!