You need a Deathfire Grasp. The Kage's gives you some good GP5 gold, and you only technically have 1 skill nuke on a champ that's played AP. You need the active to initiate, otherwise you're lacking the necessary burst. Good build otherwise! Good items and description.

AP Master Yi is too strong. I test out all my builds in Dominion, and when I was a fed AP Master Yi, my Meditate could heal more than the damage of 3 enemies right next to me! Try to add pictures to make the guild more interesting, and add screen shots of your matches with AP Master Yi too prove that this build works, even though I already know it. :D +1

I added Deathfire Grasp to recommended items, it didn't come to mind when creating the build. Now that I think about it, it really does seem like a good idea.

I do like the guide and the information within. Only real issue I see early game is the lack of mana for healing and whatnot. Also mention that this is in no way a viable competitive build. No matter how you cut it his abilities do not completely synergize with AP although they do provide a fun game. Anyway up voted, but make some tweaks.

Pretty good guide. Needs a bit more detail in my opinion, as it doesn't offer something the other guides don't. Also, have you considered Athene's Unholy Grail? It gives great CDR, and its passive works fantastically with Highlander, allowing you to mop up without running oom. I'm not a great AP Yi player, but i think Deathfire Grasp is pretty importand on him too.

AP yi is to srong lol.
Whever your stuck just meditate its like mundos ult. +1 great guide and build

No mention of Deathfire Grasp? lolbye

Core item on AP Yi

Solid build. I have played ap yi a lot and buy almost the exact same itmes. And yes i would have to agree that ap yi can out sustain almost every other mid,(except for maybe gragas and swain) keep up the good work +1
could u check out my guide? i just made it as well Alas! Poor Yorick. I knew him well