Author: MMOsite Writer Alexander Hinkley
Master Yi was one of the first champions ever released for League of Legends way back in 2009. In recent years he has gotten to be quite underpowered compared to the rest of the field, however, so he was often looked down upon by many players as not worth using. Master Yi died too quickly and just didn't do enough damage. This lack of utilization led Riot Games to completely rework Master Yi recently. After the recent overhaul, he is actually worth using now.
PS: The images below are clickable for original size.
Master Yi's passive ability, Double Strike, is the same ability but was changed to occur more frequently. The old Double Strike made is so Yi would attack twice every seven basic attacks. Now he will attack twice every four basic attacks. This sounds strictly better but they also slapped a 50% damage penalty onto the second attack. The fact it occurs more frequently is still a good thing, though, because it gives more chances for a critical hit and will also apply on-hit effects, such as armor reductions with The Black Cleaver, to your target.
Yi's best ability is still his Q, Alpha Strike. It's an activated ability that allows Yi to become untargetable for a short duration as he dashes around the battlefield (up to four times) striking opponents for physical damage. Alpha Strike used to scale with AP but now it scales with AD, meaning the end of AP Yi builds. This makes a lot more sense for a champion that uses physical attacks.
Alpha Strike is a powerful ability because it can be used as a gap closer to initiate a gank, catch up to fleeing enemies, or used during a fight to throw off your opponent's targeting for a split second. It also does bonus damage to minions so using it to clear entire minion waves and jungle neutrals is another possible use. You should definitely max out Alpha Strike first after taking a point in each of Yi's abilities.
Mediate allows Yi to heal but since it scales with AP, it doesn't end up being very useful for him nowadays. Yi takes reduced damage while healing and the heal does also get stronger based on how much health Yi is missing so it's usually a good idea to use it when you are close to death. At maximum level, it can heal up to 880 base hit points plus the bonus you get based on whatever AP you have. Meditate can help on Summoner's Rift if you are jungling but you should definitely level it up last.
Wuju Style is the real shining gem in the Yi rework. The old Wuju Style gave Yi a passive +35 AD per hit, and then he could activate it to double the bonus for a short time. +70 AD didn't really help all that much in the late game. The new Wuju Style gives up to 15% bonus AD per hit, but can be activated to deal True Damage for a short time. You read that right, True Damage. Now that can be a game changer! At max level, Wuju Style currently deals 30 + 20% AD in True Damage per hit for five seconds. This couples very nicely with his ultimate ability, Highlander.
Speaking of Highlander, it remained largely the same. It still gives him a hefty boost to attack speed and movement speed when activated while also making him immune to slows. The biggest difference with the new Highlander is that the movement speed bonus has been changed from a flat 40% to one that increases as you level up the ability – starting at 25% and going up to 45% at max. The duration is now 10 seconds flat as well.
As you can probably already imagine, activating Highlander and then popping the activated ability bonus of Wuju Style for True Damage each hit can result in your opponent's health bars melting away. It's not unusual to see late game death recaps where Yi dealt 300-500 True Damage to you. That's like getting hit with a Darius ult!
Attack speed items can help to maximize the True Damage you get out of activating Wuju Style. Zephyr is an amazing item for Master Yi since it does everything he needs. It increases attack damage, attack speed, gives him cooldown reduction, adds to his movement speed, and even gives him Tenacity. Tenacity is extremely important for Master Yi since crowd control effects (stuns, blinds, snares, etc.) really kill him because he relies so heavily on basic attacks and speed.
Master Yi is pretty squishy so items with life steal such as Bloodthirster (or Sanguine Blade on Dominion) will help in terms of survivability. Blade of the Ruined King is also a great item for him since it adds both attack speed and life steal. Vampiric Scepter is a good early-game item. Brutalizer is another core early-game item for Master Yi since it adds cooldown reduction and armor penetration. Some players also like to build Yi with a Frozen Mallet so that his targets can't escape as he hacks away at them.
If you want to go the critical strike route, obvious items are Infinity Edge and Phantom Dancer. Building your Brutalizer into a Youmuu's Ghostblade also works towards criticals. The Ghostblade is actually one of Master Yi's best items since it can be activated to increase attack and movement speed.
Master Yi is classified as an assassin, not an AD Carry (aka Marksman). To play Yi successfully, you have to be prepared to die. Your mission is to assassinate the enemy damage dealers and do as much damage as you can before going down, or pulling out. If you see an enemy who is low on health, pick them off first.
Jax is probably Master Yi's biggest nemesis thanks to his Counter Strike ability that lets him dodge all basic attacks for two seconds. Yi is also weak against champs with taunts and blinds for obvious reasons. Some other champions he has trouble with include Rammus (armor and taunt), Teemo (blind), and Fiddlesticks (taunt).
Yi is good at destroying squishy champs. Ashe, for example, can be pretty much a free kill for Yi since her frost arrows will not slow him down while in Highlander. Yi is also good at assassinating unsuspecting mages like Lux and Karthus.
In terms of teammates, any champion that can stun or slow an opponent will really help Yi out. Ashe can slow down enemies with Frost Shot, preventing them from retreating. Lux and Morgana can snare opponents while Yi cuts them up like a Thanksgiving roast.
Yi is a pretty versatile champion on Summoner's Rift. He can jungle, go mid lane, or solo top. The reworked Yi also works pretty well on Dominion.