Hey, Im DeathsJester1 a new player to league (Level 20ish). I came to league after a long time of playing WoW and games alike. One of my friends asked me to upload my build for Veigar, mid game after he saw how quickly i was managing to drain tanks hp bars..

so here goes...

The item set above is what i use for taking down opponents quickly and managing to get assists galore...

Frost Queens Claim - helps with surviving early duels
Void Staff *2 - Gives you a great help of AP and 35% magic penetration (per staff - 70% in total)
Rabadons' Deathcap - increases your AP by 30% always a must build
Deathfires Grasp - great active on this helps destroy enemies
Will of the ancients - CDR and spell vamp + AP yes please

Second set of items will have less magic penetration but higher AP, this is entirely up to you.... I tend to use the dual Voidstaff against high magic resist opponents.

In the second build i double the deathcap, meaning it greatly enhances your AP and stacking your Q with this setup, like to above the 120 mark makes for epic damage.

Q (R) E W

this allows for you to initiate with a strong first blow then the rest speaks for itself... the stun is vital before using your e, making it much more difficult to escape from.

just repeat this or you could start with your ult then q-e-w to win depending on your mood.

Pros :
Ranged AP
Exceptionally high burst damage
Bonus AP from your Q stack - remember last hits on champs give you more bonus AP)

Cons :
Squishy as hell
slow mobility (can buy boots I personally don't bother with them)
can be hard to learn to play dependent on your own playing style.

Hope this helps at least someone out there. This Champ is very good once you get to know him youll find it second nature to deplete hp bars down to nothing, which allows your assists to climb through the roof. If anyone has anything to add please feel free to comment below and I will add what needs to be added