General Guide by
Not Updated For Current Season
My IGN: is Master2of2league and I am currently a Silver 3 (22LP) Master Yi main. I am ranked as of now as the 266th best master yi in NA. (http://www.leagueofgraphs.com/rankings/summoners/na/masteryi/page-3) Now, you might have seen a tonne of guides on master yi being played in the jungle, but let me tell you: After playing over 150 games on yi overall, mid lane yi is much much more stronger then jungle yi. The reasons for this are:
1. Jungle camps have been nerfed in xp in season 5, and most of the time (if not always) junglers in experience and levels compared to solo lanes.
2. Master Yi requires items to be good. Simply put, you get more gold in lane then the jungler. More gold = stronger yi.
3. Master Yi is an assasin. Why would an assasin even go into jungle in the first place? Think of it, what other assasin goes into the jungle? Not Zed, Talon etc...
4. Having ignite as a second summoners spell really adds a punch to your burst. Combined with the combo of q - e - (yomuus if available) - aa - (bortk if available) - ignite - aa -aa is more then enough to 100-0 an adc or other squishy.
5. Going off of 4. This is really essential in teamfights as yi needs his resets (like kat!) and with this burst, he can get an extra q in to make sure he isnt being focused on.
6. Master Yi roaming is scary. I've had plenty of games where I simply go to bot lane and pick up an easy double kill because of his damage. After getting level 6, botrk, and yommuus respectively, his ganks become even more powerful as he can easily assasinate and stick to the lane he is ganking.
7. Waveclear with yi is HILARIOUSLY GOOD. Somegames, you can literally roam every 2 creep waves and still out cs your laner. His ability to farm with q allows him plenty of opportunity to roam, while not giving up pressure mid.
8. You are literally a second adc. It provides your team the safety of having an extra dps source if your adc is behind.
My Runes for Master Yi are as follows:
Flat hp seals (8hp) X 9 = 72 hp
Flat hp runes make him a really really strong laner/harraser at levels 1/2 and allows him to have a great kill potential at those levels. Armour runes are not advised as you will most likely lane against a mage. Even if you do lane against an ad mid, (like zed), flat hp runes will still be better for early level all-ins.
Flat ad marks (.95ad) X 9 = 8.55 ad
Flat ad runes for a champ that scales off ad. Self-explanatory. We don't take attack speed marks as ad marks are more cost-efficient.
Mr/level glyphs (firstname.lastname@example.org) X 9 = email@example.com or Flat Mr/level glyphs (1mr) X 9 = 9mr
I usually take Mr/level glyphs as the harass of most mages mid are really minimal early game, and there is low kill potential for them. Mr/level become better then flat mr at lvl 6 which is quite early in the game, and allows your mr to scale better into mid-lategame.
Attack speed quintessences (4.5%as) X 3 = 13.5% as
This is a MUST on yi. Some people take ad quintessences on yi (2.25ad X 3 = 6.75ad), but as someone who has tried both, 13.5% attack speed synergizes with yi much better then the 6.75 flat ad. Also, the cost efficiency of attack speed quintessences are much higher then the cost effiency of ad quintessences.
Masteries for yi are typically 21/9/0. I run this page on basically all of my games. Nothing in the utility tree offers much to yi, and having that 36 extra hp and juggernaut from the defence tree is huge for early trade/all-in potential.
On Yi, you always want to start with dorans blade and a health pot. This start is much stronger then going longsword 3 pots as it gives you much more sustain overall after 5 min. Also the 70 hp is MASSIVE advantage over the longswords, while the longsword only has 3 ad more.
After your first back, you typically want to buy these items depending on your position and the amount of gold you have:
<300 gold : buy 1 ward and 2 hpots
400-500 gold : buy 1 long sword and 1-3 hpots
500-700 gold and ahead: buy 1 long sword and 1-3 hpots
500-750 gold and behind: buy an extra dorans blade and 1-3 hpots
750-1200 gold: 2 long swords and 1-3 hpots
1200-1400 gold: long sword and a vamp sceptre
1400+ gold: bilgewater cutlass
After your first buy, you want to buy in the order of: d-blade -> bilgewater cutlass -> berserker boots -> Botrk -> Yommus
After, if you are really ahead you can get a bf sword for the huge ad boost. After getting a bf, get a lw asap.
If not get a lw for the armour pen.
After lw, get IE.
Finally, for the last item, get G.A.
Your final build should look like: Bortk, Berserkers, Yommus, LW, IE, GA