Kha'zix excels at countering mids with his high burst. He is also great at roaming in the mid game to help shut down your enemies. in the late game, you should be jumping in and out of team fight, securing a kill every time. a kill or assist resets the cool down or his leap, so escaping should be no problem. This build has given me a win with around 20-2-13 every time.

Champions that are slower mid champs suck as Swain, Ryze, or Brand are easily countered by Kha'zix who can dodge their main damage abilities and continue to do damage. The w on Kha'zix allows you to farm without having to trade with you opponent. this also lets you whittle sown your opponent until you can go in for the kill, remember that Kha'zix does more damage to isolated targets, so keep the minions away. Kha'zix does extreme amounts of damage and can get away with it, making him the ideal assassin. you also will only need the first or second blue from your jungle before being able to go on by yourself.

Kha'zix cannot truly fulfill his role when he is against champions that have the same role as him. these champions are Katarina, Akali, and Diana. These champions won't necessarily counter you, but they will be able to shut you out from you cs if you make an early mistake. the main problem as Kha'zix is being locked down with any stun or snare paired with a silence. Pairs such as Ryze and Blitzcrank will shut you down the very second you step out. Also, without blue buff early, Kha'zix will eventually run out of mana either guaranteeing a kill for your enemy or for you to burn your summoners spells.