Max Taste Their Fear first because it is your primary damage source against isolated targets and try to evolve it first even in the jungle because otherwise its damage is quite low I think, otherwise evolve the leap first and the your Q second. Next you'll have to max your Void Spikes since it is your second damaging ability and a nice chasing ability because of its slow, it's heal is also quite useful in the jungle. Evolve this ability last since I think your Q and E are worth maxing earlier and your ultimate isn't worth maxing anymore since the 50% damage reduction was removed. Max your E last since it will only increase its damage but its damage is not worth it. You still need to evolve it first or second since the increased range and reset on kills is necessary. And put three point in your ultimate at level 6, 11, and 16.

Kha Zix being a predator and an assassin, it will be necessary to have movement speed quintessences to chase your preys or to get in/out of battles easily when combined with your ultimate. The other runes are classic, Attack damage marks is usually necessary for Assassin's even though you could still choose to buy Armor Penetration Marks, but since Last Whisper and Black Cleaver offer high amounts of Armor Penetration you will not need these Armor Pen Marks. Finally, flat Armor Seals and Magic Resist Glyphs offer nice resistance in the early game.

A classic 21/9/0 for any AD assassin's taking any point in Armor Penetration, Attack Damage and increased damage to champions in offense while taking bonus health, armor, magic resist and reducing the damage taken from monsters in defense.

Concerning items, Spirit of the Elder Lizard should be picked first to clear the jungle easily, then rush your Tiamat and boots (Ninja Tabi or Mercury Treads) depending on the enemy team and then pick up Ravenous Hydra. Black Cleaver and Last Whisper should be picked then for the massive Armor Penetration they give. Complete your build with two resistance items suggested in the build above or a Blood Thirster. Finally upgrade your boots and trinket depending on your needs.

In teams fights your objective will be to find an isolated target, preferably the AD Carry, the mage or the assassin, sneak behind him with your ultimate and immediately take him down with your crazy damage output from your isolated Q, then follow the same procedure again and again using your reset on the leap to take down priority targets to win the team fight. this is where your resistance items, runes and masteries will be useful because you might come to be focused while trying to assassinate your main preys.

- In early game, when ganking or in the jungle, try to stick to your target by moving between attacks to land as much basic attacks and Q's as possible on your target which could result in an easy first blood or kill.
- Try to find isolated targets because as you know your Q deals massive damage to isolated targets.
- If you find your self playing Kha Zix in lane constantly pass into a brush after having used unseen threat to reset it.
- Your ultimate combined with your Leap and eventually flash is a very nice gap closer and can be used while chasing your prey or to get in and out of team quickly and painlessly. Otherwise your leap itself is very good to escape sticky situations or simply to close the gap between your and your target.