Welcome to my Tank Veigar build.

I played couple of games with this build and its pretty good.
With this build you got high survivability mid and end-game.
But also if you farmed your Q good enough, you can burst enemies down with your combo.

Pros:
- High survivability
- Great burst damage

Cons:
- Requires a lot of farming
- Not great enough against tanky enemies.
- Really squishy early game
- Without blue, you cant farm well
- Mana

Runes are pretty simple.

Mostly i'll take Magic Pen in Marks.
AP per LVL in Glyph's and Seals.
And 3 flat AP in Qquintessence.

You can also take flat AP in Glyphs and Seals or Mana Reg/Magic Res.

Masteries are pretty straight forward aswell.
Just put everything in AP for a bonus on your burst damage.

I'll start always with shoes, not with mana regen or dorans ring because Veigar is pretty slow without boots and really squishy early game.
If he gets ganked without an escape, you will be dead in a couple of seconds.

After around 1200 gold go back to the shop and buy a Giants Belt for more HP and some mana pots and a ward.

After enough farm you go back to the shop again and you buy a Warmogs. This is your primary tank item because you get tons of health and health regeneration.

If you got issues with your mana, for example, not getting blue buff. buy a chalice first.

After the Warmogs you going to take a look what kinds of enemies got in the other team, if there are more AP than AD enemies, go for Force of Nature first, or if there are more AD than AP go for Frozen Heart.

If there are more AD you buy some more armor afterwards, doesnt matter what you take, you can take a Randuims Omen or Thornmail.

With AP you can take more Magic Resistance, you can take a Banshee's veil to get some more mana.

After 3 tank items you can build further with AP, if you are against some tanky enemies get a Deathfire Grasp, if not take Deathcap first, and then DFG afterwards.

With this build you can have around 400+ AP if you farmed your Q well enough.

Remember! Always buy 1 or 2 mana pots and a ward to ward at the ramp of the enemy team in their jungle.

Farming is pretty straight easy, just run around in circles and last hit minions with your Q spell.

Every killing blow with Q grants you 1 AP.

End game you will have tons of AP with not so many AP items.

If your enemy on your lane is trying to harras you or gank you, just try to stun wuth E and harras him back with your Q and W.

At teamfights, always focus a carry, try to stun him with your E, and smash him down with W > Q > R (and DFG afterwards end game)

Always W first after stun because it takes some time that they will get damage from your casted spell.

I'll always take flash for great escapes or trying to get a kill. But if you want to farm a lot, a teleport is also handy.

With your secopd skill you can take ignite or clarity if you got mana issues.

You can always try this build.
It's fun to do something else with Veigar and getting tons of kills and not so much deaths.
Last 3 games i had all around 10 kills and 2 deaths. Because at teamfights they wont focus you.

Good luck!