What can i say Good champ

Magic pen Marks Ap per lvl glyphs flat AP Quints and Hp per lvl seals all of this runes (not mark) will help you whit your passive

10% cooldonw reduction so you can use your Q as soon it possible magic pen some AP and Spellvamp
and some onther important stuff
for masteries can you also pick 21/0/9 better spells/3ap/ magic pen/ CDR /1.5% more damage/AP per lvl/+5%AP/more damage against units below 40% health and also better spells/shorter dead time/+2% speed/+1% spellvamp

cooldown reduction boots spirit visage and will of the aincients for some more spellvamp Rabadon + Rulai's for ap + some hp also some magic pen

Q is your importants ability W is good to dodge and to farm at same als your E Ult Like Karthus' ult but short range and over time

You can also pick exaust (exaust change whit ignate)
Or ghost (ghost change whit flash)

Look out for morde he can be a pronlem his armour can block your early game damage