Thos is my Build for MASTER YI.thanks for your support if you like it!!!Pls vote for me thank you!!!

i find the poential in Yi to be Ap.But with your ulti and my 3rd move,y would u even think about AP?
Thats why i add in Guinsoo's RageBlade.With this,u can Alpha Strike someone(example.sona for 3-4 bars of health)worth it?With Guinsoo u can even strike her to death.

For marks-magic penetration is good,piercing MR(magic resist)
For seal-having more armor will increase the chance of not dying
For Glyph-having more Magic Resist will increase the chance of not dying
For Quintessence-Getting Flat AP rune is better than adding ap per lv.everyone do well in late
games,only early game is hard.

For Masteries i get 24-0-6.Getting all Ap and CD reduction+magic penetration is good.but you ned the improvement of your surge
Reason:Simple.Its give Atk Spd and A.you need Both.so upgrading it by 10% will made you pain in a *** for 12 second.

You may change Guinsoo for infinity Edge or Madred's Bloodrazor(if got super high health)

Maxing Alpha Strike and Meditate as they scale with AP

Flash,Ghost,Surge or teleport will be your best choice