In this new season: Are there any specific ways to best jungle as him? what routes should I take? what masteries and runes should be taken? What items should i build on him? When should I start ganking lanes? how do I know if my jungle is being invaded and how should I react if they do? when should I invade the enemies jungle? When should I engage a fight?
Thanks for your time and consideration
Kha'Zix has great AD scalings so early game you should focus on farming and only ganking when you're fairly certain you can get the kill and won't run into the enemy jungler. You should be careful in some match-ups vs. early game junglers since they will have the advantage until you get your items. You get a power spike as soon as you start to get some AD. For the most part you want items that give AD and armor pen. but items that give these and more (eg. Maw, Mercurial, BlackCl) are more efficient. Ideally at lower elo you want to go Stalkers->Warrior>Ghostblade>tier 2 boots>Ravenous Hydra>Last Whisper> and then usually I'd recommend a defensive item that will round out your build according to how fed you are as well as the enemy team. I hope this helps! If you have any other questions I'll try to answer them! [slayer-pantheon-thumbs]
Bit of a Kha main these days here.
First off, currently with Jax and Yi and stuff running amok, Kha's not a great pick right now, not saying you can't win against them, they just scale much better than you thanks to gunisoo's.
Anyways.
I run Flat AD Quints, Armor Pen Reds, Armor Seals, and 5% CDR/5%&18 CDR Glpyhs for 45% CDR at 18 (as an option, sometimes games don't allow me to get those items), taking Stormraider's Surge as my keystone. It gives you less damage than Thunderlords yes but proccing Stormraider's on Kha is not only stupid easy but it allows you to zoom around team fights and skirmishes in relative safety, something Kha really needs to stay ahead.
As for build
Boots you can be flexible on, though I recommend 
for when you're ahead, 
when you're not. With Stormraider's, you don't really need 
but you can trade Mobis for them if you prefer.
Is your core. Jungle Trinket is your choice but I like the vision control that 
provides. Skirmishers is probably fantastic but I never feel like Stalker's would have made a difference for me.
for Damage
For Defense
This is better than 
if you ask me. Probably a play style preference though.
Start Gromp then do Blue then Skuttle. While doing blue, don't AA too much, just kite with W and Q, kill the small golems first (every camp kill small ones first) and you'll be able to meet Skuttle ~40% hp right when it spawns, you'll leave skuttle with max hp and mana, gank mid or top if you have the opportunity, if not either go to their red if you're confident or your red if you wanna play it safe. After red look to gank, if nothing is available take dragon skuttle > Krugs > base and pick up 
.
Max Q > W > E, and evolve Q > E > W/R depending on what you need. If you're ahead, max R usually, since the enemy team probably wont be pink warding you much. But the third evolve -usually- wont make or break a game.
Tips and Tricks:
Go into a bots custom game and practice something interesting. You can E and then Q midair, duh, everybody knows that. Double Jump 101. Instead though, practice Q'ing at the start of your Leap. This allows you to maximize double jump distance or simply getting free trades in. E cancels Q animation root, so if you can't move your mouse fast enough to E>Q then you can Q>E, though with diminished effects.
The Midair wombo combo is pretty well known but I'll explain it. Basically Jump over somebody, Hydra right on top of them and Q as you fly past them, and reactivate Jump before you hit the ground to either head towards the next target or back into your team.
https://www.youtube.com/watch?v=T2_PQVIfRlg
The video quality is terrible but its a good showcase of double jump strats.
