Ok, I know this is preseason, that's why I'm giving feedback. I'm a Plat Kha'Zix main. He is a pretty OP on PBE.
See those arrows? If you follow that path, you can use his new ultimate passive for bushes and the two charges it gives to run that whole distance in stealth (with possibly a few millisecond down time in the first transition). That's a lot of "stealth", it almost feels like camouflage. I suggest having a bush limit to chaining the passive.
His new Q is farm godsend. It's both a scuttle buster and a Drag shagger with how fast you can pump out Q's. I like it, but it's going to cause some sneaky early drags that might be a little too early.
You can Q mid air from the explosive plant. This is coolio.
Poachers Dirk + boots on the first back is a huge move speed spike. If you pair the passive with mobi boots late game and his ult in bushes, he's essentially speed racer when moving through the jungle. This feels like way too much move speed, even if you only take into account boots and dirk.
(Side note, you may want to make it clear on Poachers Dirk that you have to fulfill those three charges three times, meaning you will have to clear 9 large monster enemy camps to get the Serrated Dirk, or at least that is what happened in game)
(Second side note, the 30 second cooldown for Edge of Night is too low. Needs to be 40 seconds imo)