Welcome to my first major guide,this guide will talk about lee sin the blind monk and how i play him and some explanations about my build hope you will learn something :)
Also here is my favorite song while playing lee sin (video not by me)


Well lee sin is very tanky AD caster that uses energy he got some gapclosers some assassin some tanky and very nice AD ratios
What do you need before play him?
-Lee sin (6300 IP,975 RP)
-Some knowledge about landing skillshots (takes time to practice)
-Quick hands due to his combos
And that's all

Pros + Tanky Always nice!. + High damage! + Gap closers! + Escaping tools (Can use safe guard to blink onto wards etc etc.)! + Cripple reduce the enemy movement and attack speed! + Can find stealth by using either Sonic Wave or Tempest + Using Energy + AoE Ultimate (Dragon's Rage) And AoE E (Tempest) + Powerful CC (Crowd control)

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Cons - Focused alot :( - High capped skills - Sometimes using too much energy (Depending on the player) - Vayne,Kog'maw or Madred's Bloodrazor can be VERY annoying - Blind can be annoying too (Makes passive null) - Is blind :(

Offense
Summoner's Wrath 1/1 Since we take Ghost and Exhaust why not to upgrade both?
Brute Force 3/3 +3 AD is always good
Butcher Easier last hitting and jungle
Alacrity +4% Works good with the runes and passive
Weapon Expertise Good versus other tanky dps or armor stackers
Havoc More damage dealt is plain good
Vampirism Lifesteal that works with wriggle or Bloodthirster and giving more sustain
Sunder Flat +6 ArP works very good with the runes since we got more alacrity there
Executioner Better 1v1 and last hitting

Defense
Hardiness Good against people with Sunder or jungle
Tough Skin Reduce some damage from dragon or baron or buffs
Vigor Very good for your sustain
Bladed Armor Good versus buffs

Ghost
Your Champion ignores unit collision and moves 35% faster for 10 seconds.
Now this spell is one of favorites it allows you to pass through minons and it's great for escaping or chasing
Exhaust
Reduces a target's Attack Damage by 70%, Ability/Item damage by 35% and slows its Movement Speed by 40% for 2.5 seconds.
This is awesome spell it can disable damage output completely. works well if they have fed carry it also synergies with Tempest / Cripple it also good for escaping or chasing and has a neat combo with ghost
Flash
Teleports your Champion to target nearby location under your mouse cursor.
This was a nice get out of jail card but i no longer take it due its long cooldown and less range also lee sin got a blink using his w but if you want you can replace it with something

Flurry (Passive):After Lee Sin uses an ability, his next 2 autoattacks within 3 seconds gain 50% attack speed and return 15 energy each.
This is great passive especially for tanky dps like lee sin after you use anything you will have a boost of 50% attack speed for 2 attacks that means Tempest and then using autoattacks will help you farm much better!This is very helpful at turrets too just spam abilitys to attack faster and it helps your jungle or stealing buff speed by alot and the autoattacks return 15 energy as well! Sonic Wave / Resonating Strike:
(Active): Lee Sin shoots a wave of sound in a line, dealing physical damage to the first enemy it encounters and revealing his enemies for 3 seconds. If Sonic Wave hits, Lee Sin can cast Resonating Strike within the next 3 seconds

Resonating Strike (Active): Lee Sin dashes to the enemy revealed by Sonic Wave, dealing a base amount of damage plus 10% of their missing health as physical damage (Max: 400 damage vs. Monsters).

This is amazing gap closer because sonic wave have 975 range and it is skill shot then he can dash using resonating strike which even have more range!And if you use both of the skills you get 170*2 and ratio of 0.8*2 which is amazing damage!
Safeguard (Active): Lee Sin dashes towards a target ally unit, shielding them both from damage for the next 5 seconds. After using Safeguard, Lee Sin can cast Iron Will within the next 3 seconds.

Iron Will (Active): For the next 5 seconds, Lee Sin gains bonus lifesteal, spell vamp, and armor.

Now this is amazing 1v1 tool or escaping tool or maybe saving tool!
The shield has 200 base damage which may save you but it's not the shield that makes this skill great it is the blinking utility you can blink onto wards and that is why we want Wriggle's Lantern!
Then we have the Iron Will which is just godlike 1v1 tool or jungling you get free 25% Spell vamp and lifesteal thanks to this at level 5 and 30 armor!This can even save you from death thanks to the lifesteal you might even end up with 30 health and a kill on tryn just becuase you used this! Tempest / Cripple:
Tempest Lee Sin smashes the ground dealing magic damage to all nearby enemies and revealing them for 4 seconds. If Tempest hits an enemy, Lee Sin can cast Cripple within the next 3 seconds.

Cripple Lee Sin cripples all enemies revealed by Tempest reducing their movement and attack speed. The movement and attack speed recover gradually over 4 seconds.

This skill has 1.0 ratio which is very powerful and it can reveal stealth i love this skill since it is AoE as well but it has amazing crowd control on it once this skill is level 5 you can slow movement and attack speed by whooping 60% which is amazing at team fights since this is AoE skill! And always remember this can reveal that annoying shaco or akali. Dragon's Rage:
Lee Sin performs a powerful roundhouse kick knocking his target back, dealing physical damage to the target and any enemies they collide with. Enemies the target collides with are briefly knocked into the air.

This is what i call REAL ULTIMATE first of all this has 600 base damage at level 3!
And amazing ratio of 2.0 AD only caitlyn Ultimate has same ratio as this skill
And this ultimate has no cost!!! and it's only 60 sec cooldown which is low for such amazing thing i love using this as a finisher or disrupting channeled abilities

Doran's Blade This item is pretty darn good for lee sin imo.It gives you some sustain and damage! The 100 Hp is life saving sometimes and lee sin start with high hp why not to give him more? 10 Attack damage very nice for last hitting or your (+18 damage) 3% Life steal Works great with vampirism Mastery gives 6% life steal Start!

Madred's Razors After you get the first blood or tons of creep killing you go back and buy this! The reason is very simple.
23 Armor This is just great more armor to lee sin is always helpful,15 Attack damage Now This boosts your by 27 Damage this is amazing for it! Better last hitting then before too and now you can get major hp from each auto attack (6% life steal)
And the very best of it is the passive!
Unique: On hit, 15% chance for target minion/monster to suffer 500 magic damage.
This helps lee sin so much if you like auto attacking minons or if you want to steal some nice jungle buffs.

Boots-Every player know this is very essential to anyone especially lee sin who starts with 325 Movement speed (Which is very High!) This gives you huge boost for chasing or even landing your skill shots (It is easier to land them when you are close) And lee sin will gain even more escaping tool with this one item!

Wriggle's Lantern Ok so you are back in your base once more what to buy now? THIS AMAZING Lantern! This is amazing item for any AD
First from 23 armor you go to 30! Even more attack damage 15>27 Boosts by 48 Damage!
15% Life steal THIS IS MAJOR SUSTAIN with all the attack damage you got and life steal from doran's and vampirism you will get 21% Life steal This is huge! Also remember Madred's Razors passive?This Boosts the 15% to 20% Chance And now for the seconed best thing from this item
FREE WARD!And all this in one item!

Mercury's Treads Ok So now it is the time to upgrade your boots then you should take this!
This is well known as the tanky boots Since it gives you 25 Magic resist this is very good this reduce damage from ap so early and even effective late game the 25 Magic resist also help against Sorcerer's Shoes Since they pent only 20 Mr! And now you will be alot faster too but the best thing about this is the 35 tenacity this reduce the duration of crowd control effects!

Phage This one huge wooden hammer gives you 18 Attack damage and you already know how much good is ad for lee sin! but it also gives him some tanky sustian it gives him 225 hp which is great especially for the Atma's Impaler But the passive is what makes this item so great basically your auto attacks have a chance of 25% to slow which is great when your Tempest/Cripple is on cooldown! this also builds into Trinity Force

Atma's Impaler Now this is a real item one of my favorites first of all it gives you 45 armor protecting you from thier ad carry or caster then it gives you 18% critical which helps your auto attacks deal much more damage but wait that's not all!
The best part of this amazing item is the fact it transfers 2% of your maximum hp into attack damage! each 1k=20 attack damage with this build you will have 3.5k at the end that means 65 attack damage to you!!!

Warmog's Armor Few notes before buying this. get the Giant's Belt first
Now this item give when fully farmed gives 1270 health that means more 24 damage thanks to your Atma's Impaler first of all the health it gives is just huge it is one of the reasons why you want this!but that's not all you also get 40 health regeneration per 5 which is excellent with the mass health you should get this quickly after Atma's Impaler and sometimes even before the Atma's Impaler.

Trinity Force This one is hell of expensive item but for lee sin this item is just excellent.Why? well it has so many stats in just one item first the 30 ap now this is pretty darn useless but it is a small buff to your Safeguard but the better side that it is giving 30 attack damage which boosts your auto attacks and abilitys pretty darn good but not good as Atma's Impaler then we have the huge attack speed boost with your runes and passive this item should get you 91% attack speed,which is amazing with all that attack damage and it even gives you 250 health which is always nice isn't? however it also gives 250 mana :/
And now the real deals of this item 25% to slow with aa for whooping 35% like i said about Phage this is very good when your Tempest / Cripple is on cooldown!
But the best part about Trinity Force is that after you cast ability your next auto attack will deal extra 150% of your auto attack that means if you got 100 on auto attack it will do 100+150!

Randuin's Omen I find this item as very useful for teamfights but before that let's review the item so it give you 75 armor which is amazing one of the highest armor giving items in game 350 health with your Trinity Force you will get 600 health that means extra 11 damage!25 Health per 5 which adds nicely with your warmog and 5% Cooldown reduction which is very nice since the Sonic Wave / Resonating Strike got some high cooldown and when you are attacked there's 25% chance that the attacker attack speed + movement will go down by 35%!
But the reason that we so want to get this is because it is amazing in teamfight it has AMAZING synergy with your Cripple For example they got glasscannon tryn with high attack speed criple lowers his attack speed by 60% and then you use Randuin's Omen which lowers it up to 95%! and even if no it is AoE -35% movement and attack speed for the enemy team!

Bloodthirster Ok so now it is probably end-game and you deal chunks but want more? sell that Wriggle's Lantern for this first of all this item got 25% lifesteal and 100 attack damage and i think it is ridiculous the base stat are 60 ad and 15% lifesteal but after farming 40 creeps it will give 100 ad and 25% lifesteal it is lost on death but common you are so tanky and you won't die ;)

Sunfire Aegis Now this item is very nice gives 45 armor which is always good and 450 health which boosts your attack and 35 AoE magic damage per seconed personally i'm not a fun of this item at all the price is too big for small magic damage and just 45 armor
What to replace: Warmog's Armor, Randuin's Omen

Force of Nature Now this is very awesome item for the price of it it gives you +40 health regeneration per 5 and +76 magic resistance which is just huge magic resistance for its price you see that kog'maw or that bloodrazor? Then buy this. magic resistance is a counter for them!
And this also gives +8% movement speed with your movement speed i doubt you will need it but it is always good but the passive is what making this item to such awesome item you restore 0.35% of health every second!this is very helpful with the chunks of health you will have
What to replace: Randuin's Omen, Bloodthirster

Frozen Mallet Now this is a huge frozen hammer lol
It gives 20 attack damage which is kinda meh but useful nonetheless. the health it gives you is madness 700 health which is 14-18 attack damage thanks to Atma's Impaler and even more tanky but its passive is just AWESOME your auto attacks will slow your enemy Movement Speed by 40% and it has 100% of being activated which is just ridiculous for chasing enemys
What to replace: Randuin's Omen, Trinity Force, Warmog's Armor

5v5 Is pretty standard for lee sin he can go into any lane and wreck it

Top
Lee sin can solo top very well he don't have anyone that will interrupt him from hitting his Sonic Wave / Resonating Strike but the creeps,Since Solo top is mostly 1v1 lane lee sin can dominate it is recommended by me to try 1v1 the enemy as much as you could i also recommend putting wriggle's ward on the brush that junglers usually come through so you can escape or juke

Middle
Same as top but i recommend not to over-extend at all let the enemy to push and not you and be very careful since most of the middle is ap champs

Bottom
At this lane i recommend basically to farm alot it is easy to reveal ganks here using your Sonic Wave / Resonating Strike and place the ward near dragon and not in the brush

3v3 Lee sin dominates and shut off games here so easily!

Top
This is easy 1v1 as much as you can,also put ward on dragon so you could escape your w can breach walls!

Bottom
Lee is monster here as well just make sure to harrass and poke alot

Dominion Lee sin don't shine here. make sure you are bottom since usually bottom got squishies

Credits to jhoijhoi for the template, which you can find here the banners too!

Taneren-http://www.mobafire.com/profile/taneren-136993 For linking me jhoijhoi's guide and helping in other few things!

LoL Wikia For skill desc and numbers http://leagueoflegends.wikia.com