Accidentlly posted this without being logged in. This is my build. Hope it doesn't cause any confusion. Any suggestions are welcome. Also a note, i dont know how to change it but dont get rid of the sourcerer's shoes, instead ditch the haunting guise. This is my first build so dunno how to change that yet.

Havent been able to finish this build much. Usually games end faster than I can finish. In game by the Rabadon's cap you should have around 500 AP and with the runes and items around 60 magic pen.

You could also vary the abilities a little more. Sometimes I do a few more event horizon's b/c im not able to hold them still for long enough, sometimes I do more Dark matter early on to help the farm. It is nice to lvl the 'q' because that way you can farm up your AP faster. Sometimes I have around 50=60 ap before I even go to get an item.

Typical Veigar Strategy applies, stun, spam dmg abilities. Careful to not key stroke too fast. Sucks when you miss your ulti b/c you were hitting other buttons faster.

Whats really nice about this build is that you will be doing around 500 magic damage, with the ulti its close to 1000, and then thanks to the magic pen, they will normally have negative magic resist. Its really nice if you can freeze a group of the enemies, shoot with dark matter to nuke them all down around 1/4-1/2 health, focus 1 if you can to take them out, step back let team swoop in, assist in mop up when abilities are back up.