As discussed here:
Quint~ Speed or Magic Pen
Red~ Magic Pen (Flat. I don't even think you can get /LVL)
Yellow~ HP (I use flat)
Blue~ Mana Regen. (Go for /LVL)
9 Into Offensive. This is obvious because you want as much magic pen as possible.
21 into Utility
-3 Good Hands
-1 Blink of an Eye
-1 Presence of Master
You will have to put in 1 point in a tier 3 previous talent. Your choices are Spatial Accuracy, Perseverance, Expanded Mind or Greed. You won't be getting very many buffs until level 13+ and you don't take clarity.
You will need another point to get last spell. Choose from Spatial Accuracy, Perseverance, Expanded Mind or Greed again.
Spatial Accuracy (If you use tele as an escape ever, get this. It could save you many, many times. I would take this first)
Perseverance (Up to two more points you can put into this. It's worth about .08mp/5 and even less hp/5. I don't recommend it at all)
Expanded Mind (This will be worth about 25 mana per point. More later in the game. Won't go past 50/point though. You could take it, I guess.)
Greed (Well it's worth about a ward or two. Maybe a consumable end game. If you want to cookie cut it, get spacial and this)
Overall, take any combo of Spacial, Greed and Expanded Mind. I go for the Spacial/Greed because they are things that give me noticeable bonuses.
Now, you are all set. Take Teleport and Flash as your spells. In game, get any degree of starting items you want. Take Doran's and an HP pot if nothing is going to happen and you will lane till six. Take wards and potions if you are dealing with junglers. If you want, try bringing a brilliance and some potions, at level 6 activate the potion and watch heroes you aren't sure will die, die anyways.
After that, get sorcerer's boots. You now have 4 -MR things already. Your passive, the masteries, runes and the new item. Work towards a void staff next. Then abysmal.
Now is when getting items does not become a priority. You now have 6 -MR. I'll give some numbers later when I can get them. It is a rather high amount. If they don't get any magic resist, you will put them below 0.
Now get a brilliance potion and some wards if the enemies are being stealthy. Grab dragon as much as possible and start ganking with your new brilliance potion. When you have a surplus of money, go get... DUN DUN DUN. A SUNFIRE CAPE. Your -MR will help with this and heroes who get no MR will take more than 40DPS. With your ulti you will crack out about 1500 damage.
As for skills, max fear then wind. Get ulti at six and drain last. At 6 make sure to get a kill. Stand in bush and ulti, use flash if needed (NOTE: YOU HAVE TWO FLASHES HERE. YOU WILL ALWAYS BE ABLE TO GET TO A HERO. Fear them when you are there. Silence at end of fear). Congrats, that was an easy kill. Do this all game and you will be golden. You will not be able to push, but win team battles easily. Coordinate your team so they can push. You have to take hold of your team if you want to win and make sure they do what's right.