Why should I Play Rengar ?

Rengar is really fun to play if ahead.
In low elo you get feeded pretty much every game, that means every game is fun!
He is easy to pick-up if you know the assassins bread and butter.
After just a few games ,you get used to his mechanics and start getting creativ.
Earlygame

Pros and Cons

Pros:
+ Insanely fun to play
+ High Burst / One Shotting
+ Variation on Fero Spells
+ Attack speed steroids
+ Bush Jumps
+ Very adaptive
Rengar is one of the best Solo Queue Jungler since he was released, due to his very unique Duel/Assassination Kit. He has the ability to 1v1 nearly every jungler in the early game and his clear speed is very good ( he's even faster with his first camps than graves !). You won't get bored because you can play him in so many different ways and you have to adapt every game item/playstyle wise.\

Cons:
- Hard to master
- Very unique Playstyle
- Rip if they group
- Only Camouflage
- Interuptable ult
- Countered by tankyness
Rengar is a double-edged sword, either you get ahead and stomp or you get stomped. It's hard to come back, if the enemy plays it correctly. He needs to engage and you will most likely die, when the targets you need to engage on won't get one shotted. So you have to try to get ahead early by utilizing your strengths and try to compensate your weaknesses.

About the Demon

Before I start to tell you about the Combos, how to play him and his items I'll introduce you to his Kit. For this purpose I use the League of Legends Wikia .
I will mark the most important things for you (instead of shortening it) .

Starting with his passive:
Unseen Predator EFFECT RADIUS: 50 SPEED: 1450



INNATE: While in Brushmaker brush or Ambush 2 camouflaged, Rengar's basic attacks gain 600 bonus range and cause him to leap to enemies beyond his normal Melee role melee range. This bonus lasts for 0.5 seconds upon exiting brush or stealth. Leaping when on 0 Ferocity generates 1 Ferocity.

FEROCITY: Rengar generates 1 Ferocity whenever he casts a basic ability. Upon reaching 4 Ferocity his next basic ability is empowered, can be cast independently of its basic version's cooldown, incurs no cooldown of its own, grants Rengar 30% / 40% / 50% bonus movement speed for 1.5 seconds, and consumes all of his Ferocity. Reaching 4 Ferocity with Savagery or Bola Strike locks its empowered version for 0.1 seconds before and after casting it. All Ferocity is lost after being out-of-combat for 8 seconds.

Bonetooth Necklace Green
BONETOOTH NECKLACE: Enemy champion Damage rating takedown, within 1.5 seconds of being damaged by Rengar, grants him a Trophy, up to one per unique enemy champion and to a maximum of 5. An Head of Kha'Zix additional one is made available through the event The Hunt is On! Trophies grant 1% - 36% (based on Bonetooth Necklace Green trophies) bonus AD as bonus attack damage.

So basically you get Stacks for every Champion you damaged in the last 1.5 s and get bonus AD for them. You can look up which stacks you already got by hovering over the icon of the passive above your skills. But that's just a nice to have, the more important thing is that you get 1 ferocity whenever you use a skill. You get a Fero for free, when you have no ferocity and attack someone out of a bush or when you jump onto him.

Savagery Q: COOLDOWN: 6 / 5.5 / 5 / 4.5 / 4



ACTIVE: Rengar's next two basic attacks within 3 seconds gain 40% bonus attack speed, with the first also dealing bonus Attack damage physical damage and having 25 bonus range.
BONUS PHYSICAL DAMAGE:
30 / 60 / 90 / 120 / 150 (+ 0 / 5 / 10 / 15 / 20% AD)


EMPOWERED ACTIVE: Savagery's bonus physical damage is increased to 30 - 240 (based on level) (+ 40% AD) and applying it grants Rengar 50% - 101% (based on level) bonus attack speed for 5 seconds.

Savagery resets Rengar's basic attack timer.

This Spell is where your DMG comes from. You use it to reset your AA, to speed up in your jungle when you have no camp to clear or you won't make it to the next one with full fero.
Your Fero Q gives your even more DMG and Attackspeed for the next 5 Seconds.


Battle Roar W: EFFECT RADIUS: 450 COOLDOWN: 16 / 14.5 / 13 / 11.5 / 10



PASSIVE: Rengar stores 50% of the damage he's taken in the last 1.5 seconds as Grey Health (75% versus monsters).

ACTIVE: Rengar lets out a battle roar, dealing magic damage to nearby enemies and Heal power healing Rengar for his Grey Health.
MAGIC DAMAGE:
50 / 80 / 110 / 140 / 170 (+ 80% AP)



EMPOWERED ACTIVE: Battle Roar's base damage is modified to 50 - 220 (based on level) and additionally Cleanse cleanses.

Rengar's W is his backup/aoe spell. You store 50% of the damage you took in the last 1.5s and heal for this amount when you use your W. Your empowered W is also a Cleanse, so you can jump in do your combo and when you get stunned just press w and run out.

Bola Strike E: TARGET RANGE: 1000 COOLDOWN: 10


ACTIVE: Rengar throws a bola in the target direction, dealing physical damage to the first enemy hit and Slow icon slowing them for 1.75 seconds.
PHYSICAL DAMAGE:
55 / 100 / 145 / 190 / 235 (+ 80% bonus AD)

SLOW:
30 / 45 / 60 / 75 / 90%

EMPOWERED ACTIVE: Bola Strike's base physical damage is increased to 50 - 305 (based on level) and using it Root icon roots its target for 1.75 seconds.


Now to his only CC-Ability. Your E is a slow which gets stronger per point into it and when you throw a 4 Ferocity E onto someone, he's snared for 1,75s.

Thrill of the Hunt R : EFFECT RADIUS: 2500 / 3000 / 3500 COOLDOWN: 110 / 90 / 70


ACTIVE: Rengar channels his predatory instincts, becoming Ambush 2 camouflaged after 2 seconds and gaining bonus movement speed for the duration. Attacking or casting most spells ends Thrill of the Hunt.
CAMOUFLAGE DURATION: 12 / 16 / 20

BONUS MOVEMENT SPEED:40 / 50 / 60%

Rengar gains True Sight icon true sight of the nearest enemy champion, who he can leap to deal 50% AD bonus physical damage and reduce their armor for 4 seconds.
ARMOR REDUCTION: 12 / 18 / 24
The nearest enemy champion to Rengar alerts all allies within 1200 range about his presence.

This is the essential of Rengar's Kit which makes him a real Hunter. He gets one with his surrounding and enters camouflage mode. When Rengar is in Camo he gains movespeed, true sight on the nearest enemy, keeps it and can jump on someone. So you try to scout as much as you can before oneshotting. However if you come to close to the enemy, he will get an ! as a warning above his head, that you are near and marked him. You reduce the Armor of the target you jump on and deal bonus damage when the target was marked.

Combos

ONE SHOT COMBOS
With Full Fero
Full Fero Q+JUMP -> MID AIR E + W + TIAMAT +Fero Q

GANKING OR WHEN YOU COULD GET KITED
Q+ JUMP -> MID AIR E + W + Tiamat + FERO E or try to gather some stacks before the best is full fero and JUMP+ FERO E +W + Tiamat + Q

WHEN YOU GET BURSTED / CC'D
Jumping in either with Q or not , midairbola tiamat w -> FERO W

Early Game

Let’s talk about Rengar’s pathing in the Jungle and how/when you should gank. Rengar can choose between many clears, I’ll show u some popular ones to begin with.
But before that some clear help:
try to kite the camp
try to generate fury before you start your red buff and jump 1:22 on the blasting cone with Q, this way you already have 2 fury when you start the buff and can q him instantly again for another stack.
And keep in mind that you don’t need to burst the jungle camps, so just reset every AA you can with a Q. So instead of Q mid-air on a camp, you jump and instantly q after you did your jump aa on the target you want to kill.

Mid game

Now you want to get your passiv stacks.
It is pretty good if you already killed the enemy toplaner in earlygame because they usually get quiet tanky, but if not try to ks in teamfights or so.
Waiting at the enemy's buffs is a good idea if you got a teammate with you, but only do this if you are sure you two can take him down or you are ahead.

Late Game

Don't forget to farm!!!
In teamfights you want to camp in side bushes with no wards in them (check the bush with red trinket) and the most important thing is like for every assassin to let your team or the enemy team ingage but NOT you.
If you ingage you will just explode.
Run behind the enemies with ult on and watch out for the stun abilities. the best moment is when tanks are busy fighting with your team, the sups are a bit away and burnt their cc or shield/heal spells and the best of all moments is when everything i mentioned before happens and the adc does such a thing like mf r or jhin r.
if the adc is dead or really far behind, your priority will be to destroy their midlaner or maybe, if feeded, their squishy jungler.
Be really carefull when you try to make catches because most of the item they wont walk around alone.