I used to main Veigar, then i stopped, and I still sort of play him. He is hard to play in ranked/draft since he is an easy counter pick.

Pros:
- Bursty AF late game
- Out Damage Everyone
- Easy wave clear
- Can take Tower Easily
Cons:
- Squishy
- Slow

The most important thing to do as Veigar. You last hit with your q as much as possible, and prioritize siege minions to normal minions. Once your q hits Lvl 3 you can W Q caster combo minions; you can also start poking your enemy with your q.

I take Attack Speed to add to Veigar's insane turret takedowns, and AP cause Veigar is an AP champion obviously.

Pretty Standard AP Burst masteries, the weirdest thing might be teh vampirism, but in my eyes, 2% spell vamp can get you out of more sticky situations then 15 ap

This build focuses on split pushing and taking enemy towers. R.O.A. is for survivability, Rabadons for AP, Void staff when people come and try to stop your pushing, Sorc boots to run away, Nashors to kill towers in 5 seconds, and Rylais to kite.

Max your q first for the maximum amount of possible AP from kills/assists. Then level 3 for your e since 2 second stuns are pretty long, but more then that is too much, so then go max your w since it is your main damage ability late game.

Flash because you have no escape if you can't land your e, and TP because you are bursty but slow, so it can be used for more map pressure. Get Heal for normal Bot lane Carry