Hello everyone, I am a trash tier Jhin player who is in love with his aesthetic and game play. I made this guide for fun but if it helps anyone then I suppose that's pretty cool too. Also this is my first ever guide and I have no idea what I'm doing, hopefully it's readable.

Jhin has a highly unique kit and that is what makes him so strong and so damn fun to play. I'll give the literal ability descriptions and then I'll break it down after in plain english.

Whisper

DEATH IN 4 ACTS: Jhin's basic attacks use ammunition and his attack speed cannot be improved except through growth by level-up, and his attack speed growth is classified as base attack speed. Jhin can attack 4 times before having to Disarm icon reload for 2.5 seconds, and does so automatically after 10 seconds of neither attacking nor using an ability.

The fourth attack is guaranteed to Critical strike icon critically strike, dealing 15 / 20 / 25% of the target's missing health bonus Attack damage physical damage. The fourth attack will still critically strike against structures, but deals 44% reduced damage and doesn't apply the bonus physical damage.

EVERY MOMENT MATTERS: Jhin's Critical strike icon critical strikes grant him 10% (+ 0.4% per 1% bonus attack speed) bonus Movement speed icon movement speed for 2 seconds, but his critical strikes deal 25% less damage.
Additionally, he gains 4% - 44% (based on level)「 (+ 0.4% per 1% critical strike chance) (+ 0.25% per 1% bonus attack speed) 」 bonus Attack damage icon attack damage.

Dancing Grenade

TARGET RANGE: 550 EFFECT RADIUS: 400 COST: 40 / 45 / 50 / 55 / 60 MANA COOLDOWN: 7 / 6.5 / 6 / 5.5 / 5
ACTIVE: Jhin launches a canister at the target enemy, dealing physical damage. Dancing Grenade bounces to up to three additional enemies beyond the first, with each kill it performs increasing its total damage by 35%.
MIN. PHYSICAL DAMAGE:»
45 / 70 / 95 / 120 / 145 (+ 40 / 47.5 / 55 / 62.5 / 70% AD) (+ 60% AP)

Deadly Flourish

TARGET RANGE: 3000 COST: 50 / 60 / 70 / 80 / 90 MANA COOLDOWN: 14
PASSIVE - CAUGHT OUT: Enemy champions damaged by Jhin, his allies, or inside a blooming Captive Audience Lotus Trap are marked for 4 seconds.
Deadly Flourish
ACTIVE: After a delay, Jhin fires a shot in the target direction, stopping at the first enemy champion it collides with, dealing physical damage. Deadly Flourish deals 75% damage to non-champions along the way.
PHYSICAL DAMAGE:»
50 / 85 / 120 / 155 / 190 (+ 50% AD)
Damaging a Caught Out champion Root icon roots them and grants Jhin Whisper Every Moment Matters' bonus movement speed.
DURATION:
0.75 / 1 / 1.25 / 1.5 / 1.75

Captive Audience

TARGET RANGE: 750 COST: 30 / 35 / 40 / 45 / 50 MANA + 1 CHARGE COOLDOWN: 2
RECHARGE TIME: 28 / 27 / 26 / 25 / 24
Captive Audience
PASSIVE - BEAUTY IN DEATH: Jhin summons a blooming Lotus Trap under every enemy champion he kills.
Additionally, Jhin periodically stores a Lotus Trap, up to a maximum of 2 stored at once, which are unaffected by Beauty in Death.
ACTIVE: Jhin places a Lotus Trap at the target location that lasts for 2 minutes. The Lotus Trap blooms if an enemy walks over it, Sight icon revealing all enemies caught inside for 4 seconds.
Blooming Lotus Traps Slow icon slow all enemies inside for 35% for 2 seconds before detonating, dealing magic damage to all enemies caught in the explosion. Lotus Traps deal 65% damage against non-champions and champions recently hit by one.
MAGIC DAMAGE:»
20 / 80 / 140 / 200 / 260 (+ 120% AD) (+ 100% AP)

Curtain Call

EFFECT RADIUS: 3500 ANGLE: 75° COST: 100 MANA COOLDOWN: 120 / 105 / 90
Curtain Call
FIRST CAST: After a brief delay, Jhin begins Channeling icon channeling for up to 10 seconds, during which he has the ability to cancel or reactivate Curtain Call up to four times. The camera will zoom out during the activation delay.
Curtain Call 2
SUCCESSIVE CASTS: Jhin fires a Curtain Call 2 round in the target direction dealing physical damage to all enemies hit, stopping at the first enemy champion it collides with, Sight icon revealing them for 2 seconds and Slow icon slowing them by 80% for 0.5 seconds.
MIN. NON-FINAL PHYSICAL DAMAGE:»
50 / 125 / 200 (+ 20% AD)
Curtain Call 3
Curtain Call's damage is increased by 0% - 250% (based on target's missing health), and the Curtain Call 3 final shot Critical strike icon critically strikes for 100% increased total damage.


Ok I know that was a lot but once you get a feel for Jhin it becomes pretty straight forward.
Jhin's passive is centeral to his identity as a champion and serves as the core of his game play and build paths.

Whisper:

Jhin's has 4 auto attacks before he is forced to reload for 2.5 seconds, Jhin will also reload if he doesn't attack or use an ability for 10 seconds. The time between each auto is set and cannot be shortened besides Jhin leveling up, any attack speed you build will be converted into movement speed and damage which brings me to the fun part of Jhin's passive, Crits.
On crits Jhin gets additional movement speed that scales off of his bonus attack speed. Jhin's crits do 25% less damage but that's just because all the damage has fled to his 4th shot.
Jhin's 4th shot is an automatic crit and does missing health damage, this still applies to structures however does reduced damage.

Dancing Grenade:

Jhin's Q is a lock on ability that bounces to 4 targets, gaining damage for each target it kills as it bounces. This ability is best used to farm, poke in lane, and add a little more damage to a target before landing a 4th shot. Takes a little while to learn the bouncing mechanics but it's a strong tool in trades.

Deadly Flourish:

Jhin's W is one of the longest ranged basic abilities in the game. It can be used to farm or poke but it is best used to root enemies marked but other damage. When Jhin hits a marked enemy with his W he roots them for a short duration and get the bonus movement speed as if he had just crit them. This ability lets Jhin pick off enemies or hold them in place for an easy 4th shot trade in lane.

Captive Audience:

Jhin E is his most underrated ability. It provides a small amount of vision and upon activation creates a fairly large AoE slow that also give vision of the target that activated it. This makes it perfect for maintaining bush control or defending from ganks. You can even throw it down mid fight to utilize the slow to stick on a target or run away from one. At later levels the explosion actually does considerable damage so its not a bad idea to use your W to root a squishy over one of them.

Curtain Call:

Jhin's grand finale gives you an overhead view of a large cone, Jhin has 4 skill shot bullets each one slows the target slightly on impact, the forth shot will crit and do missing health damage. Hitting a champion grants vision of them for a short while and the slow serves as a good way to start a team fight. It's difficult to land all four shots consistently but doing so will do a large amount of damage. This really is a performance and feels bad to miss but so so good to land.

There are several different rune builds people take on Jhin depending on personal preference. The runes i have included in this build are my preferred runes as the movement speed and damage gained from hail of blades in not only too good to pass up but it's also a ton of fun to use.

The other main keystone used by Jhin players is Fleetfoot work due to its sustain and small burst of movement speed.

For secondary trees I usually take precision with hail of blades, however that is generally pretty unorthodox. Most prefer to go into the sorcery branch and pick up gathering storm and celerity, and I can see why that would be strong and would even recommend that. I just enjoy the precision branch purely for Triumph and Coup de Grace, again for the fun I find in the extra missing health damage and the potential life saving health from Triumph.

Any combination of runes serves a similar purpose and all are functional, in the end it comes down to preference and play style. To start I recommend Fleet Footwork as a keystone to give you additional safety in the laning phase as you begin to learn how Jhin plays.

Lane

Since Jhin is such a unique champion that it take most people a long time to figure out his play style especially when it comes to farming. In oreder to CS efficiently you need to get a feel for Jhin's reload, as it can cause inexperienced Jhin players to miss farm. I would recommend either practicing farming in the practice tool or in normal games before taking Jhin into ranked. During the laning phase you can use your 4th shot to threaten a trade with the enemy adc to push them off of farm, if they don't back off you can get a free trade on them. if you happen to land a q bounce on the enemy adc you can then use your W to root them and land another auto or ideally a 4th shot. Once you get stormrazor you can very easily tap the enemy and then run away or chase them down continue to chase depending on the situation.

Fights

In team fights Jhin plays a little awkwardly, as he doesn't usually have the consistent damage to melt tanks but he's usually too immobile to get into position to blow up enemy carries without putting himself in danger. Jhin needs to walk that fine line between ballsy and reckless, using his damage to soften up the enemy front line while making sure he cant be caught out. That being said you can use either clever positioning or Rapid Fire passive to land a shot onto an enemy carry, this can do half of their health or more so doing so can win your team the fight in certain situations. Jhin in not meant to tear down tanks or power down objectives, but what he can do is delete squishy champs and turn a team fight into a performance. The key to late game fights is stay alive and make sure you don't waste a single shot since every bullet matters.

Jhin is an insanely unique champion who is extremely fun to play when you know what you're doing. He truly is an artist and he will make you feel like one when you're playing him. Good luck and I hope this has help at least a little.