Good Day Fellow Summoner I am BacardiSuperior and I will be explaining my Over powering Yi Build.
After Master Yi's Last update he has been made a much stabler jungler which allows you less trips back to heal up and give you more opportunity's to Gank and Destroy the other teams Assets and Turrets. There is one down side to being this powerful with this build... you will be targeted and you Have lower Hp.

Like Stated Before with the last update on Yi he is more stable for Jungling. This means that he can solo blue as his first kill but i still recommend you get a leash it will work out better. Start with blue and at lvl 2 get Alpha Strike and go to the wolves and Alpha strike the middle one (Orange one) and finish them off with physical attacks. Next got to the Wraiths, Alpha Strike the Blue one and Physical the rest of them. Now if you are low HP I suggest you take the golems before red and what you do is Alpha strike the bigger one and then physical the smaller one for the life steal then Smite the Bigger one and then get your W which is your heal and heal up because you have blue. Now you should be good to go for Red, Alpha strike red and Kill one of his little dragons and then smite him when its done cooling off and physical the last small dragon. Go back to the Wraiths and kill them again. If the other team does not have a jungler then go to their blue and then Wolves, and if they do either gank top or mid or go to your wolves.

The Runes is Use are
9- Marks of Desolation
9- Seals of Defence
9- Glyphs of Celerity
3- Quintessence of Desolation
You do not need to Use these but i suggest you Keep the same Marks,Seals and Quintessesnce but you could change the Glyphs to Attack Speed, Crit, or Mana Regen.
I have not tried these other glyphs so i do not recommend them

If you chose too you don't need to use my items but i suggest them because i have tested this build.
The last 2 Items "Guardian Angle" and "Thorn Mail" are The 2 items I add in Deppending on the team i am going against. If i am being targeted in team fights and they are Heavy AD I sell my "Wriggles Lantern" And get both of those items. For the most part i only get one or the other but its up to you what you do with these.

To Engage into a team fight I ues Q after in the fight I auto attack along with my Ult to quickly Kill enemys.
Your Ultimate is good for people that are running because you hit it and then use Q to jump on them and you slow them with Exhaust and keep beating them to death.
For a Ultimate Like karthas's Your W is perfect to counter it, If he is ulting you press W and it gives you Move Arrmor and magic resistance and you take less damage.

Pros
Good Life Steal
Good Attack Speed
Good Jungling
Good Ganking
Good BackDooring
Stealthy
High Dmg
High Crit
Cons
Low Hp
High Value Target
Easily CC'ed
Easily Ganked and killed

I Use Smite and Exhaust when i play Yi. This build is for a jungler so Smite will always be one of your summoner skills. Some other skills that may be useful for your way of playing that will work with this build are: Ignite,Flash,and Cleanse. Smite is Jungle Yi's Best friend because i can not tell you how many times it has saved me in all the times i have jungled with him before and after the patch. I use Exhaust because i do not like kills to get away from me so will Exhaust and my ult i can keep them close well they run away if i did not have the chance to get Red.

Well I hope this is helpful to all players New or old. If this guide does you some good make sure you Like it up and leave a comment on how well you did or to even suggest some changes that need to be made for different playing styles.
If you want you can even add me one LoL, My Name is BacardiSuperior and if you are lvl 10 and Under you can add my Smurf so i can play and not put you into high Levels and it will be more fun. BacardiRazz is my Smurf.
Hope you guys have fun with this Guide and i hope to see you in game and lets dominate the LoL World with this Master of All Master Yi's