Who am I?
i am a average League enjoyer maining Jungle. I hit plat my second season with a couple of thousand games played in total.
Im gonna hit 300k mastery points on my main in a couple of weeks. I would say i have enough qualified knowledge to make a guide.

Why play Kayn?
Kayn is the only and best jungler for adapting into a team comp. He can be an unkillable bruiser with sustain for days. Or he can become the most annoying oneshotting assasin with few or none counterplays.
As a champ he has great mobility which allows risky plays and a playstyle with high action. He is also a great champion with simple abilities yet it dosent get boring.

What is Kayns Abilities?
-Kayns Q Reaping Slash is a dash which does damage twice. First damage is the dash and second damage output is when he swings his hoe. Its possible to jump small walls with this abilities like dragonpit or the wall behind Gromp

-Kayns W Blade's Reach is a long slash which either knockups or gets extendend range

-Kayns E Shadow Step is a movement ability which allows kayn to go through walls for an duration of time. It gets cancelled when Kayn leaves the obstacle for a little duration

Why Play Kayn?
-He can easily dive and escape
-Great damage output
-Mistake friendly

Strong sides
-If played probably can easily carry
-Can 1v5
-Dont waste 50 years clearing the ****ing Crocs
-Never the same with the two forms.
-Insane for onetricks
-Healthy Jungle clear

Weaksides
-Loses hard early in alot of matchups
-Need knowledge about lanes and lanestates to not be useless
-Blue gets outscaled in 99% of matchups. So gotta end fast
-3 Unplayable matchups which are played alot

When Clearing on kayn the most important tip is q'ing into the wall to make more time for basic attacking.
1. Normal full clear
My favorite pathing is Red Buff- Krugs- Raptors- Murk Wolf- Blue Buff- Gromp- Scuttle. When doing this pathing you will only need to smite once so you will be able to fight/Steal scuttle. For the optimal clear its important to smite the big Wolf as fast as possbile as you will be able to take the camp in 2 Q's.

2.When Against slow clearers.
When against Junglers that dosent full clear you can easily punish them by pathing your full clear towards their crocs. So when against a nunu like jungler you should always own 7 camps instead of 6. And then invading is ofcourse free if you know where the jungler is.

3. Invade start
IF and only if you know where the other jungler starts you can steal their buff and possibly a flash if you start next to them on their Raptors or Wolves. Then you take them fast with q and then E over the wall and smite it. Then with your level diff you can start killing them until you see enemies moving towards you and then escape. This will set you up for prio in the whole game as long as you dont throw your lead.

My Favorite Clear for Darkin
For fast form when top isnt ranged bot is the optimal spot for ganking. So sometimes you have to start blue. When starting at the Bluebuff your first Skill would be Q and the second would be w and third then E. So Lvl 1-3 is Q-W-E and then back to normal leveling. Camp bot and get form ASAP. Even when it means laneganking and loosing some Jungle tempo

I dont mind getting form a little late as long as the other jungler dosent get ahead. It is not worth forcing wack ganks for a little itty bitty part of your form. You gank when enemi lane is pushed and when you can get a kill or summonnerspell. Even in form you are kinda weak before goredrinker. The Optimal back for form should also be with goredrinker as you will then be able to snowball into oblivion. Also when you play against Nunu/Amumu and other ganking junglers you should punish them by getting fed on cs and if you can tell drake/Herald is a loosing fight just go and trade the other objective if possible. DONT INT FOR FORM. So Prio 1 is Farm. 2 is form and 3. objectives.

When to go what form?
Rhaast is way stronger than Darkin in many ways. But in games with squishy top or 3+ mobile squishy champs Darkin might get a chance. So as a base rule 3 squishys then Darkin is viable. Rhaast is way better at Darkins job than Darkin is at Rhaast job so when in doubt go Rhaast.

Rhaast
When taking flash or ghost on kayn you should be thing about how well you can stick to your target when fighting. So when playing versus a kindred/Graves or people with a knockback like Jayce ghost is viable so you can get knockbacked and get back in the fight. But when verus a lux/Veigar or other zoning champs just take flash so they dont catch you and make your teamfighting bad.

Darkin:
Always run flash. Need it for the cheeky plays.

Goredrinker

★I like goredrinker way more than Eclipse as the burst healing is very clutch. It 9/10 times makes you able to do at least a Reaping Slash and Blade’s reach

Eclipse

★ Run this when against a full squishy team as you no longer need Black Cleaver. And it will make you almost instantly oneshot the squishies.

Muramana

★Manamune is a very strong item when ahead! If you got enough gold to buy a tear on an early back you can easily get to the 1v9 part. The item has a very strong spike. Buy it if you got 1500 gold and can get Whip and tear or something with raw stats. As mana alone won't really make you stronger. Manamune is Very good and only viable when you know you are about to carry the game. Items like Cleaver or Death's Dance are stronger if you are behind or just on equal with the enemy jungler..

Black Cleaver

★As long as the enemy has someone stacking armor i advise you to get the cleaver as its very strong against tanks and makes you able to 1v1 all tanks with Goredrinker and Cleaver.

Death’s Dance

★Always get this item when the enemy has some kind of ad. The healing on it is great and the passive is synergizing greatly with kayn’s Kit and sustain.

Maw of Malmortius

★Get This when they have bursting mages like veigar/ Lux/ Brand. As it makes you able to tank the whole combo and than heal it all up with the omnivamp passive. .

Spirit Visage

★It's a very strong item especially when you have a healer on your team like soraka/Yuumi. When a Yuumi is in your team Always get it. It is a good replacement for maw when the enemy team doesn't have Burst but more magic damage over time like Viktor/akali who doesn't instantly can burst you down.

Serylda's Grudge

★ This item is very strong when you pair it with cleaver. It should never switch with Clever but it's a very strong combination when you are against like 3 tanks. As you already then will have like 60% armor pen.

Ravenous Hydra

★ This item is new and I'm not yet totally sure about it. But it's strong as an third item with the healing and high AD. Buy it far ahead.

Chempunk chainsword

★ This is the best anti heal item for kayn. When you are not the enemy's main target. As they don't need to hit you for it to work.

Thornmail

★Very good item when the enemies are heavy on AD and healing. Buy this when you are the enemies main target.

Prowler's Claw

★ This is the best but hardest mytic on darkin. Its early damage and raw damage stats are very strong. If you only know how to full send in all fights. DONT ATTEMPT WITH THIS ITEM.

Duskblade of Draktharr

★This item is probably the easiest yet one of the strongest items. Works well when you need to dive the backline even through peeling. Go this item when you will not be able to escape after an assasination.

Muramana

★This is a must on Blue kayn as you are spamming abilites like crazy also the damage output is crazy..

Youmuus Ghostblade

★ My favorite second item. You should get this after form. With the Snowball runes and form you will be everywhere like a permanent nocturne ult. You are oneshotting any squishies you see and can snowball for a couple of minutes before the laning phase is over.

Serylda’s Grudge

★Get this everygame when anyone is slightly out of your oneshot range.

Serpent’s Fang

★This item is very situational. When they have a shielding support or ability this item is very important as it pierces through shields.

Umbral glaive

★This item is rarely viable but get it if you got an insane first back buy it for the raw stats and gank opportunities

Edge Of Night

★When against People that can stop you completely from engaging. Like Veigar or taliyah .

How to play Rhaast
Kayn is very good at snowballing. Make your lead through constant flow of cs. No need to scrimmage if there isnt form to get and noone is dying. When you got form. Trust yourself.
You have the perfect tool for survival. Play like it. Never die with ult. If you dont have any abilities left press R. No need to just stand there.

How to play Shadow Assasin
When playing Darkin get your form and start hunting. You can dive almost any situation with the Combo W-Q-AA-R-Q. After that get out wait for cooldowns and reengage. Early and Mid game is where Darkin is best and easiest. The late game is difficult unless you are turbo fed. So focus on early objectives and snowballing your other lanes because the longer the game last the bigger the chances of you loosing. End fast. Get both heralds and snowball other lanes. If that isnt possible go kill the carries and ignore the frontline. Oneshot the most fed enemy and try you best to take a few with you to the grave. You will not survive without flash unless the position badly.

How to Use R.
When playing against people with Zhonyas. Prioritize people without. Its no problem if they do. After ulting them a couple of times you will know when to use your R.
Some people get scared of Kayn and spam zhonyas. Just wait out the zhonyas and then R out again. Your ult has a longer time than Zhonyas no stress.
Ult isnt just a healing tool. But you can dodge big cc abilites even when full HP. If you are scared that you will die. Dont risk it. Press R. A Kayn without R is better than no Kayn.

if you are scared of getting caught. Get to the walls. All the short walls are bypassable with your Q and use E for the big walls.

Stealing Objectives
Go to the website Smiterino and practice. When you have dont that you are ready. Kayn is great at stealing objectives. You fly into dragon/baronpit and then R someone. Wait for drake to be low and smite. YES you can smite while untargetable.

Runes for Rhaast

Conqueror

★ Conqueror for Kayn is a perfect fit. The rune makes you stronger in longer fights. So a already strong teamfighter Rhaast with extra AD and Healing

Triumph

★ Triumph is very easy to make valuable since you just need to get assist or kills to get the healing. And Kayn is in the middle of the enemy team getting some hits in with his massive AOE

Legend: Tenacity

★ Kayn is only ever vulnerable when stunned. So lets get stunned less.

Last Stand

★ Since kayn is always kinda low yet nowhere near dead. This makes Last Stand very valuable since it grants adaptive force.

Conditioning

★ Since Kayn are mostly building HP and AD some resitances will do him good. Alot of people want to take Boneplating but it dosent really makes sense as it dosent help you nearly as much in the jungle as on a lane.

Revitalize

★ This rune is Great with the precision runepage and also Kayns passive The Darkin Scythe: Rhaast as his whole champ and kit has ALOT of healing.

The Shadow Assasin

First Strike

★ Grants great damage and very good for an early damage .I like this over dark harvest as it makes me snowball and carry early/mid. And Dark Harvest Isnt going to make a very big difference in late game

Magical footwear

★ Since kayn dosent use stopwatch or hexflash. Why not get some free gold?

Future's Market

★Future's market lets you hit spikes earlier as Serated dirk. And you can often have more good recalls.

Approach velocity

★ When going through walls its procs when they are in vision.and its great for gapclose

Sudden Impact

★ Kayn Is dashing constantly so its free damage.

Treasure hunter

★Good pairing with the primary rune which both increases your income. Also easy to complete since Blue kayn is is everywhere .

Secret and honorable Tips

If you are making an escape but almost get caught. Press E and flash into a wall. When pressing E you can just flash into the middle of an obstacle.

R*2?
Yes you can R twice almost instantly. I discovered this in a game a couple of moths ago. If you get mordekaiser Ulted. Tank him for a couple of seconds and then R him. When his R runs out your will aswell. But you get your Ultimate ability refunded. But without the healing. Might be a glitch. But use it to your advantage and make them ragequit.

Last but most important.
Your smite makes you able to ult. So no need for flashing through cages and stuff like that Avoid it by smiting and spamming R