for this build to succeed you have to know how to play rengar fairly well, and it shouldnt be too hard. basically what you do is you start krugs, ward your red, and then do your chickens (i dont know their real names im talking bout the little fire shooting birds) after you do your red with your smite. the reason why I choose not to do red second is that by warding it you can see whether your going to get invaded by the enemy jgler, and I also find saving smite for red gets you more health in the end but thats just my opinion. what i do after however is check on mid, if your mid is being pushed try to look for an opportunity to gank for them if the other mid laner is overextended, if everything is all well just get scuttle and move to your top camps. a personal note is that i prefer not to gank bot until 6, and mainly camp top and mid until 6. At your top camp smite gromp kill it and move to blue, then assess your opportunities at top and mid and see which is gankable and if none are just move to see if scuttle is still alive to kill. As a very lazy pleb thats all i really got to say, camp top and mid, then 6 gank bot and snowball yourself hard. to get the fullbuild you will have to sell your jgler item WHICH YOU NEED TO BUY FIRST late game, and please note this build is expensive as hell so you better get killing fast.