http://www.youtube.com/watch?v=lxEvOZJD5hk

Kha'Zix is a tanky DPS asassin Jungler, some people play him on top but i rather play him in the Jungle.
He has good ganking potentials, and with exhaust you will almost have an instant kill.
He has a bit of a rengar playstyle and go can go in stealth for a short period, his passive and ultimate are a good combo for a constant slow.

[*] Kha'Zix's passive is Unseen Threat. when Kha'Zix leaves the line of sight of all enemy champions, his next basic attack on a champion deals bonus magic damage (+0.5 AP) and slows them by 35%.

[*] Kha'Zix's W is Void Spike. It's a 1000 range line skill shot that does 75/115/155/195/235 AoE physical damage at reaching the end of its line, or when it comes in contact with an enemy. If Kha'Zix is within the AoE effect, he regenerates 40/70/100/130/160 health (+0.5 AP).

[*] Kha'Zix's E is Leap. He jumps to a target location with a range of 600, and deals 65/100/135/170/205 AoE physical damage in an small area around him.

[*] Kha'Zix's ult is Void Assault. He goes into stealth for about a second and gains 40% increased movement speed. It can be used twice within 10 seconds before going on cooldown.


Kha'Zix's ult also allows him to evolve one of his skills* each time he levels up his ult. Each skill can only be evolved once, and evolving a skill gives him a graphical upgrade:

Taste Their Fear: Receives a large damage buff equal to 12% of the target's missing health, increases the skill range, and your auto attack range is increased as well. His claws grow larger.

Void Spike: Fires 3 spikes instead of 1, and applies Unseen Threat. The spikes protruding from his shoulders become larger and more numerous.

Leap: Greatly increases his leap range by nearly double and refreshes Leap's cooldown after getting a kill or assist. He grows wings out of his back.

Void Assault: Can be activated 3 times before going on cooldown, and while in stealth, he takes 40% reduced damage. He becomes red.

*Apparently, if you can score a pentakill with Kha'Zix, you receive a forth evolution point. Also, if you kill a fully stacked Rengar after your third evolution point, you can also get a fourth point.

I think Kha'Zix is a strong DPS, he can also initiate teamfights and walk out safely a bit later.
when you initiate the enemy team with Leap (E Ability) and walk out with void Assault (R Ability)
they will focus you, and when they focus on you, youre AD Carry will have a free fight.

I hope u will learn from this Information i gave to you, and i wish u lots of fun playing Kha'Zix

i would recommend:
1: leap (E) for easier ways to gank, and late game for chasing enemies.
2: youre Q ability, for more damage output and for 1v1 fights, also this makes youre ganks on top and midlane way more effective.
3: i would recommend W instead of evolving youre ultimate, if you evolve void spikes use youre ultimate and use youre void spikes (W) you will almost the entire enemy team, because now, when you evolved youre void spikes (W) youre passive will work on it.
so:
1: E
2: Q
3: W