Disclaimer: I don't really play ranked much, so this may or may not work out in ranked matches.
My thoughts on Lee Sin:
Lee Sin is my absolute favorite champion, and I've tried many many different builds with him. Most of them were alright, some I didn't like (atmog's), and in general I did pretty good (good as in lots of kills, not too many deaths) but doing "good" isn't enough because this is a team game. Building him just so he can kill other champs didn't have enough impact on the game imo. So I decided to try out coming up with my own ideas for him. I decided that yeah, he can do great damage build as an AD assassin/DPS champ, but then you're not taking advantage of the utility he has to offer. He has two stealth revealing moves, a knock back/knock up, a shield, and a AS+MS debuff. That's quite a bit! Although his "CC" isn't like fiddle's fear or taric/sion's stun... it's stilll very good. The cripple can nearly cut the DPS of a carry in half, the knock back/knock up can win team fights or secure kills, and the shield can save teammates. The thing is, although he is good for damage, his only really "good" damage skill is his Q. His ult is strong, definitely, but it's more useful for utility than damage (unless you're "asassinating" someone). You're not going to ult kick someone as part of your normal DPS pattern. You'll use it when it's the right situation. Anyways, after realizing that he has a bunch of utility in his kit, I thought that it would be best to have him survive enough to actually be able to use it. Atmog's Lee Sin/AD Lee Sin, etc just seem to fall short in either damage or survivability imo. Trinity Force is a common item for Lee, but he really needs another item to do decent damage. Also, warmog's + atma's is great and all, but it won't protect you much from the carry, nor will it help your team much. So, after thinking about all these things, I came up with my own slightly modified build that I feel helps your team out a lot with debuffs and auras, keeps you alive, and enables you to output plenty of damage.
Yes, I know that the mana on BV and TF are a big waste but... It's really not a big deal. You can go FoN if you REALLY want, but I prefer having the extra HP and spell shield. As for Trinity, well, that's just too bad. It's a great item on Lee Sin once you get the hang of timing his skills and everything.
I would say that the core of this build is:
-Emblem of Valor
You want to build the first 3 items first (HoG before the others) and then work on getting your Trinity. After you have Trinity, it's up to you. I prefer getting Warden's Mail, a Negatron cloak, then finishing Stark's. That's my usual order, but you always have to mix it up depending on the enemy team.
Item Build Explanation:
This is kind of the boring part and I'm going to fly through this real quick because it's late and I need to get some sleep.
- Well, if Lee Sin is CCed, he can't be using his skills/utility, and therefore makes him less useful. Also, the MR is a big help due to low base MR.
- Lee Sin has 7 skills, all use in a constant rotation to take advantage of his passive to maximize DPS. Trinity Force synergizes too well with this characteristic of Lee Sin. The MS, AS, AD, AP, etc are also beneficial to him
- Yes, Lee Sin has his passive for AS, and Trinity. However, having even more AS helps you to weave in your auto attacks easier which in turn keeps your energy up. Also, the stark's aura is awesome (AS,LS,-armor)
- The active is AWESOME, the passive is great, the health is beneficial, and CDR helps kinda, and etc etc. All around great survivability item. Synergizes well with cripple.
- Everyone knows why this is an awesome item. The shield can potentially block a nuke. It gives good MR, and the health is very much needed. The mana... eh, it's worth the waste.
- Part of his Q does magic damage, and tempest does magic damage. The spell vamp DOES help. Also, the AP makes your shield stronger, and the LS/AD helps obviously. The active will help with chasing (makes it easier to do your Q - R - Q combo... chase chase chase, hextech active, run up, EE to cripple, run in front, Q - R - Q)
I feel that each item I've chosen for Lee Sin helps him out quite a bit. There's no big wastes with these items other than the mana, which is worth it imo.
**As Lairai said in his post, Lee Sin is very versatile so paying attention to how your team is doing and how the enemies are doing is one of the most important things a Lee Sin player can do. Your have team mates building tanky? build more DPS. Your team is very squishy? build more survivability. And remember, health comes before resistances in early game. That extra 45 armor won't help so much if you only have 1.2kHP.
I've been experimenting with different rune set-ups, and right now I've been using ArP reds, dodge yellows, MR/level glyphs, and MS quints. You get armor from activating your W the 2nd time, so I thought dodge might prove more beneficial early game since he already has a way to get extra armor. It's been working really great for me. However, I've also had much success with ArP reds and quints, armor yellows, and MR/level glyphs. I prefer to throw in one AD quint when I use that set-up, but that's just me. Either one of these set-ups should work fine. I would suggest slightly different masteries for each set-up, however.
If you're using dodge yellows, I'd suggest 21/9/0 and get the dodge masteries (and go 3 in armor, 1 in MR since you're missing out on the armor from runes).
If you're not using dodge, I'd suggest either a 24/6/0 or a 21/0/9. I quit using 21/0/9, just my preference, I prefer the 24/6/0. With 24/6/0 you want the CDR, the AS, the MPen, the ArP, and the rest should be obvious. MPen works with part of your Q and your E. It's not too shabby on Lee Sin, but you wouldn't want MPen runes, obviously.
These are the two I ALWAYS use on him. Flash is amazing, obviously, and exhaust will shut down anyone who does more damage than you.
Ghost/Ignite/whatever can work, but I highly recommend flash and exhaust.
I almost always get boots and 4x hp pots (wait for the 4th.... make sure to tell your lane mate not to attack any minions. you won't lose any exp/gold if they don't). Depending on your team, you may decide to go for early ganks or w/e so 3x hp pots is fine too.
Try to sit back and not take too much damage during your early levels. You should get Q first, or W if you feel like it, but I prefer Q. Once you hit level 2 and have both Q and W, then it's time for the fun. As long as you know your enemies, you can easily harrass them and do some serious damage with a Q-Q combo, then W back to safety. You will want to avoid laning against someone like Leona, Veigar (especially Veigar), or Sion as they can stun very easily and, if they're smart, can stun you right as you fly to them/their teammate.
During this early phase, it's a great idea to quickly double cast your shield (so you get the lifesteal/spell vamp) when you're about to last hit a few minions. It'll heal you a little bit, and every little bit counts!
As soon as you have over 900g, you should go back and your HoG and a ward (always get wards!) and then use the rest of your gold on HP pots. I almost never leave the base without 1 ward and 2-3 HP pots if I can fit it in my inventory. The HP pots are amazing, most people don't even realize it. If both you and your enemy are 1/2hp, pop an HP pot and go after them. Rarely do people remember to use HP pots DURING a fight, they usually use it AFTER. This gives you an 100-200HP advantage on them, which can be HUGE in the early game.
When you can, get your emblem of valor, and now you should almost never have to leave your lane. HOWEVER, if your team doesn't have a jungler, and you know your lane mate can solo for a bit, go ahead and go jungle some. With emblem of valor and 2 points in your shield, you should be able to jungle without losing any HP except for on buff golems.
Skill order for 1-6:
Q W Q E W R
TIP: Once you hit 6, going for a kill might be a good idea. Hide in the bushes, and when you see an opportunity, Q someone, run up to them, R them away, then Q back to them again. If you're really good and have full energy, you can Q, AA E AA R Q etc etc (basically weaving in auto attacks and throwing in your tempest as well for extra damage). The lower you can get them before your 2nd Q hit, the more damage you'll do. You can also use your tempest to quickly slow an enemy, get in front of them, Q - R - Q them back to your teammate.
By mid game, you should AT LEAST have your boots (preferably boots 2), HoG, emblem of valor, and hopefully a piece of your Trinity already. I would recommend getting either phage or zeal first. I can't give you any math or anything behind this, but it's just always worked better for me than getting sheen. I really really LOVE movement speed and being quick, so zeal has always been one of my preferred items anyway.
SO, you have a chunk of your core build, some wards, hp pots, etc. You'll want to run around and farm jungle creeps as much as possible, keep your lane protected, and look for gank attempts. Lee Sin is a great ganker once you get the hang of him, so always be on the lookout for opportunities. When I gank, my usual combo/order is something like...
-Q - Q to enemy, or flash in and R then Q - Q to them again.
-Double cast your tempest (quickly hit E E) to cripple them and prevent them from escaping.
-Proceed to use your passive to finish them off. Avoid using your shield, save it for a quick escape (also, it doesn't provide any extra damage/cc to the enemy... so in a way it's a waste of energy. if you use your shield and don't have energy for you Q - Q to finish them off, you should beat yourself). If you Q them in close range, make sure to hit them twice before Qing again.
-If needed, exhaust will almost always ensure a kill on your enemy as long as they aren't too close to their turret/flash is on CD.
Finish off your trinity when you can, then look for what you need next. If they have a strong AD champ, go for warden's mail, then randuin's if needed. If they have a fed AP chemp, negatron cloak. If you're surviving just fine, go for stark's.
Also, I often times get the red and green elixirs during this phase of the game. They give you a bunch of HP, AD, AS, and some crit. And crit is surprisingly useful on Lee Sin, but don't ever try to build him like a tryndamere.
Once you have Trinity, Stark's, Randuin's, BV, and your boots... you're almost unstoppable. Not quite as unstoppable as maybe a cho-gath or morde or whatever, but you're more mobile, can do more damage, and can heal up very quickly. In teamfights, you'll want to use your R to either knock up as many people as possible, or to take out the biggest threat. Your primary goal should be to destroy their squishy carry. This should be fairly easy with both cripple AND the randuin's active. You'll cut their DPS in half, easily, and you'll still be hittin them like a truck. Your Q-R-Q combo can probably take out half a squishie's health, then when you've Qed to them and start hitting, you'll have your Trinity proc up so your next attack will hit them hard too. Then, the rest should be fairly easy after you've crippled and randuined them. If you can't get to their carry, your secondary goal should be to protect your own carry. You have a shield, a knock back, and a cripple + randuin's active. If you see a crazy tryndamere going after your ashe, shield your ashe, then cripple the tryndamere and kick him back in to his own team. He'll have both his AS and MS slowed, and it'll take a while for him to get back up destroying people. Also, just a general tip, use your exhaust on their highest DPS champ. So that would be someone like a fed yi or cait or something.
I'm not sure what else to say about late-game... You're pretty much a tanky-dps with some utility to keep your teammates alive, and to lower the enemy's DPS. Take out their carry, protect your carry, that's all their is to it. It takes time to get used to maximizing your DPS with Lee Sin, so keep practicing if you feel like you do no damage.
If you happen to get a hextech gunblade... you should be extremely tough to kill. Your tempest is an AoE magic attack, so if you hit 3 people for 250ish damage (highly probable) then that's 750ish magic damage, and 25% of that is like 180-190! That's a pretty good amount of HP to heal off of your tempest! And with stark's, gunblade, AND your W you get like 60-70% lifesteal, that's a hell of a lot! You should be very difficult to kill at this stage of the game with a butt load of HP, a butt load of resistances, and a butt load of lifesteal and spell vamp. Of course, if you get focused and CCed down, you'd have no chance, but you're not likely to be focused as long as you don't jump straight in to their team and try to single handedly ace them.
-Ward hopping: place a ward on the other side of a wall, or wherever, and immediately jump to it. With one of the more recent updates, this will reveal the ward temporarily, but can save your life.
~ Some Lee Sins like to get wriggles (junglers usually) and it's often smart to go to dragon with your ward available on wriggles and if someone comes to gank you, simply ward hop over the wall (then as they run around to chase you, Q - Q to the dragon and escape unscathed).
-(one of my favorites) If one of your enemies is low hp in lane, and you see them moving up to get a last hit (but you're out of range of your Q) simply shield dash to the minion, then Q - Q get the kill . This is usually unexpected, enemies generally just stay out of your Q range if they're low, but they don't always remember that you can dash to a minion as well. This same "trick" or tactic can be applied for ganks/kill attempts. Shield to a minion and kick them back with your ult or whatever.
-Your tempest and sonic wave (E and Q) reveal stealthed enemies. Make sure to use them to make akali/teemo/eve/twitch/wukong visible when they try to hide.
-Use your sonic wave to check bushes before entering them, especially right when you get to your lane (to avoid the early gank).
-When jungling, you can Q - Q through walls to the next minion camp, drastically increasing your jungle speed (I don't know if this applies to straight jungler lee sins)
-You can quickly self cast your shield by pressing alt+W which can save your life at times due to it being quicker than clicking. Also, I feel that it's easier to press alt+E when you're 1v1ing someone and you're keeping your passive up and shield is the only thing off CD.
-When taking down a turret, always take advantage of your passive. I've seen so many lee sins who simply AA the turret, and it annoys me to no end. Shoot your sonic wave at the air and take advantage of that extra 50% AS!
Anyways, good luck to you all! I've just had so much success playing with this build/play style (and I know it's not way too unique, but the build is different from the norm, and most people don't transition from laning to jungle/lane in the early-mid game like I do). I'm sure a lot of the other guides tell you the same stuff I just put in to mine, but hopefully I picked up on something another guide may have missed.
Here's a pic that shows my success with Lee Sin (the builds for the lee sin games are all what I described... the build shown in the pic is my wukong build lmao)
And I put up another one, just to show you guys that I'm not lying to you lol
Polite comments/suggestions are appreciated!
EDIT: I noticed that the pictures are extremely small... I'm not sure how to make them bigger, sorry guys! If someone could tell me how, that'd be much appreciated.