This is my basic set up for Kha'Zix and is primarily for a semi to full agro top lane. I did not include wards or potions in the build so buy them as required. The best way to go about playing agro is to act like you're going for some CS and Q them when they're close, unless you can get an early kill, i usually wait till level 6 and have evolved Q to try a 1 v 1. Do not let them kill you early, play passive against you're counters and wait for ganks from jungle in which case, E then W for slow and then you're jungle should come in and you should have no problem getting the kill or exhausting a flash. Also, a lot of people i've seen rush manamune, its a terrible idea, build tear and start building up the 750 you need and you should get it around the end of the build. You need damage first not manamune, so get a brutalizer. I've tried bloodthirsters on Kha, but the never seem to work very well, a lot of life steal is not necessary.