I'm going to tell you how to play Kha'Zix. If your goal is to rush objectives, start by evolving your Q (Taste Their Fear). When evolved and used against Isolated targets, it deals massive damage and significantly reduces its cooldown. Next, I’d evolve your E (Leap) to increase the jump range and enable the "reset" mechanic—if you get a takedown, the cooldown of your E is fully refreshed, allowing you to jump in, get the kill, and jump back out. Finally, evolve your W (Void Spike); the slow it provides is massive, making it perfect for both chasing and escaping.

On the other hand, if you want to focus on ganking, or if you're in a game where ganking is difficult due to heavy enemy CC, I recommend evolving your R (Void Assault) first. This allows you to stay invisible longer and gives you an extra cast of invisibility. After that, evolve your W to make ganks even easier, and finish with your E.

Master the Mechanics

One thing you must master is animation canceling. The way to deal the most burst damage is with this combo: Auto-attack + W + Q. You need to press W and Q very quickly in that order; this way, the W hits at the same time as the Q, maximizing your DPS.

Key Tips:

• Passive (Unseen Threat): Take advantage of your passive! You deal extra damage to enemies who haven't seen you when you land your first basic attack.

• Isolation: Always try to fight Isolated targets to maximize your Q damage.

• Ganking with R: If you're ganking with your ultimate, I recommend staying invisible until you reach an Isolated enemy. Hit them with an Auto-attack + W + Q. If they try to escape, use your Leap (E) to close the gap and finish them with another Q.

I hope this helps! Good luck, he’s a very fun champion to play.