This is my tank troll Veigar build. Now it may seem ridiculous at first but don't knock it until you try it. He is a bit weak at first but with proper farming you will be nuking faces left and right.

You want to go with your typical m pen m reg and ap setup that you like best. You can also go with survivability build but I like the damage for late game.

Once again go with either mag dmg with some utility or you can go with defense with utility. Your choice.

This is my first build so I'm a bit guide illiterate but these are the items you want.
1)Rylai's Crystal Scepter
2)Sorcerers Boots
3)Force of Nature
4)Warmogs Armor
5)Rabadons Deathcap
6)Thornmail

Depending on the other team you can switch 3 and 6 out if you feel it necessary.
You really want to get warmog's and force asap for that extra durability and survivability

As always with Veigar, max your q first, followed by w, and finally e, getting your ult at levels 6,11,16. The most important thing here is to farm your q as much as possible. Since getting kills with it increases your ap, this is very important for this build. While playing last hit with your q when possible and while it is on cooldown last hit with your basic attack to increase your farm since this build is pretty expensive.

I like flash ignite but use whatever you feel necessary to aid in victory.

This build seems ridiculous at first but it ends up doing quite well. You have to be very careful at first because you are very squishy and dont do a whole lot of damage early. With proper farming this build does tons of damage. Since I have no idea how to post my scores on here I can tell you that I win 90% of the time always with a positive k/d. My most recent game ended with me as 21/3 on TT. I ended up with well over 600 ap with farming q. If your tired of the normal old caster role, I suggest you try this troll build a nuke faces off of faces.