What do you think about high burst damage yi while also being able to chop chop chop towers in seconds?

Pros

Strong mid against squishy ap/ad champions
Extremely HIGH early game damage and still able to push down towers with ease like dps yi
With blue buff very sustainable
OP heal
High survivability and great escape mechanism

Cons

Any strong cc is a counter (eg Fears/silences/stuns/suppresses)
Mana dependant early

Just the normal Ap rune page

MARKS: Magic pen Marks for mid/late game buff

SEALS: Mana regen per level for the laning sustainability

GLYPHS/QUINTS: Flat Ap Glyphs and Quints for that early game domination (having a 150dmg alpha strike at lvl one is OP)

Normal Caster Mastery page, giving great buffs on AP and CDR

Having 3 points in magic resistance will help you take less damage in mid lane

Having reduced death time allows getting back into action for more farm and exp (farm = gold = better items = win!)
1 point in the summoner spells reduces flashes cd by 15secs and 2 points in mana regen helps with lane sustain

Early Game
Early Game Doran Rings stack is highly effective. Having 3 should give sufficient health, mana regen and AP to succeed in lane.

The boots of speed purchased after the 1st dorans ring, which you will upgrade into a
1. Ionian boots of lucidity for the CDR
2.Sorcerer's Shoes if you lack magic pen runes
3. boots of swiftness if you are dominating
4. Merc treds if you are being focused with cc
before you purchase your Rabadons Deathcap

In my opinion I like to purchase a mana pot along with a Dorans Ring when I recall if I do not already have a blue buff (your jungler needs it more than you)

Mid Game
The Dorans stack for early game should give sufficient farming or even killing ability to allow you to easily purchase your Rabadon's Deathcap straight up.

From there get Lich Bane for extra burst after you alpha strike your target.

Late Game
The Zhonyas will help you survive when Meditate or Alpha Strike is on cooldown during teamfights (You are dependant on your alpha strike to put out massive damage and your meditate to stay alive)

I then get Morello's Evil Tome which gives a decent amount of Ap and great CDR which will allow you to spam out more of your OP Alpha Stike (pretty much 800dmg to their whole team)

Lastly a hextech gunblade gives great life steal and spell-vamp to regain health during the cool downs of Alpha Strike and Meditate

Summary:
1.Max out Alpha strike 1t becuase it will be your main damage output
2.Then max out meditate as it is your 20 second cooldown Zhonya's/Kayles Ulti
3.Place a skill point whenever you can for your Ultimate Highlander
and place the remaining points on Wuju Style

(preferred) Flash
An easy escape mechanism or chasing gap closer

(preferred) Ignite
An easy way to finish off a low champion turret hugging
(alpha strike at them, if they don't die from that, ignite the champion and walk out of turrent range) If they are still alive just keep farming and let them go back to base. Its better to be alive and farming then to die turrent diving or to come out with so little health you have to recall

Ghost
is also nice summoner spell to close gaps with fleeing champions or to flee yourself if your ulti is down

Exhaust
Also a decent spell to keep the enemy from escaping as you wait for the cooldown on your alpha strike which will deliver the finishing blow

Leave comments on what you think.

In my opinion Yi is a devastating mid champion or solo top champion
Nothing beats high survivability, sustainability,great harass and high damage.

Tips:
When laning and poking them with alpha strike try aim for minions close to them as it will ensure you get a hit on them without ending up next to them under their own turrent :S

Alpha strikes 800dmg to the whole team might not seem that powerful, but it will be devastating to their squishy carries hiding behind the tanks.
Your role is to screw over their squishies unable to hide behind their tanks from your alpha strike

In most scenarios you may end up dead but you will have also taken down two of thier carries leaving offtanks and tanks to be finished off by the other 4 ppl on your team

Good luck and have fun with my build, you'll be sure to find success in mid lane :D