This is very defensive build as you can see. I will explain items, runes and masteries in following chapters. I play with this build, without sound in game, and my frame usually drops to 10 FPS even lower and I still manage to carry the team. So I hope it will work on your makro PCs even better. :)

Most players would say 10/20 or 14/16.. I think that's WRONG! Firstable get your missing AD from rune + Doran's Blade to active your special ability. Some players put point in Ignite.. It's 10 AP.. and I put that point in Tenacity. So 4% damage taken > 10 AP. And now whats with 14/16.. You don't really need 6 armour penetration wich takes u 3 points wich u could put in Ardor wich gives u both attack speed and ability power, and it's more effective to change 5 AP rune into 2 AD and take less damage.

First is Doran's Blade: Some health for survability, DMG to active your specail and 3% lifesteal is great in combination with spell vamp.
Boots of speed: Not to much to explain.
Sheen: Great in combo with your q skill, it provides huge burst damage.
Mercury's treads: Now stun and silence are your biggest enemys, this helps alot with it. If there is not much stun and silence in enemy team you can feel free to take Boots of Switness or Socrer's shoes.
Ryali's Crystal Sceptre: I usually have much problem with enemys getting away, so this is great solution beacause of it's passive. Plus gives u more survability and AP.
Lich Bane: Now when you already got some more AP and survability, Lich Bane is great, crazy amouts of damage, enemy will just cry.
Hextech Gunblade: Always rember to buy Hextech Revolver first because AP is adding to your Lich Bane's special. So HG is great at this point because you already have around additional 80% dmg to your auto-attack so it's 60 AD turns into ~105 DMG with bonus lifesteal and spellvamp.
Rabadon's Deathcap: Gives you crazy AP at this point, and you deal so much DMG that you can just go from enemy to other enemy and kill them one by one.
Guardian Angel: Yes, you are not a tank. Even if someone manage to kill you, you come back, cast your W spell and depending on situation run or keep killing. :D