Hello and Welcome to my Guide!!!Be patient with Rengar until ferocity bar is full or at 3/4 .Rengar is very effective with full ferocity bar and able to take the full advantage of rengar's passive.Try lure the fights to the bushes and try to use ultimate(thrill of the hunt)wisely when try to gang or for some skirmishes.At team fights wait until main tank start the fight and focus to the most squizy champion or focus on the champion who does the most damage from the enemy team.Have Fun and Good luck,i hope to join my Guide,its my first try and i dont want to be talkative,i want to be comprehensive.

Pros / Cons

Rengar

Pros

+ Great burst and AS steroid with Savagery
+ Unseen Predator allows him to catch enemies off guard and set up ganks from bushes
+ Tanky without having to buy much defensive items
+ Slow / Snare CC
+ Decent built in sustain
+ Short CD Stealth that revels all enemy champions over a large area
+ Bonetooth Necklace makes killing enemy champions that much more rewarding

Cons

- Easy to harass early game
- Counter-jungled easily
- Ultimate can be countered by Oracles