PSA: Veigar is spoopy again
Today I learned that spamming q off cooldown as veigar with only the mana regen mastery cannot run you oom, and you will have enough mana to cast other spells frequently. He also uses both the mage keystones well (look at that, now he has his old ult ratio back, not to mention +10% on q and w, or a giant movespeed bost for pressing r).
Not to mention since the turret changes (roughly 25% increase from the ratio alone, nevermind resistances) your autos are brutal to towers. With merely 800 ap I was taking them down nearly as fast as an ad champion (since the damage is equivalent to 400 ad with no attack speed boosts).