Veigar, no question. His Ult has a 1.2 AP (+0.8 enemy AP) ratio, his W has a 1.0 ratio, and his Q has a 0.6 AP ratio.

In 5 seconds, I'd say AD carries already do more damage than any caster with equip comparable to 1000 AP equip.
350 AD, 100% crit + IE bonus, 2 ATK per sec means 8750 damage.
Only 5250 in 3 seconds.

Sooooo...AD carries are the better bursters. Q.E.D.

Honestly withh 1000AP I'd say Malz. All of his abilities scale extremely high, and his Null Zone would be dealing 18% of your max health every second. So standing on it for 5 seconds would deal 90% of someone's health.

I graphed this all out once. It turns out Veigar placed about the middle.

The highest was Fiddlesticks. Next was LeBlanc, and after that was Xerath.

Lowest was Kassadin, followed by Ryze.

That's only 2.8 + .8 of the enemies AP.

Malz full combo scales 2.9 + 18% health/second with 1000AP

To anyone saying it's Veigar, it's not.

Veigar has a full AP ratio of 3.4 + enemy AP

Fiddlesticks has a full AP ratio of 5.8 + superior bases.

Fiddlesticks also has about 3k damage in bases.

You most certainly didn't 1 shot Galio, since you only have 10% MPen.

Also, he said with 1K AP, not whatever build you want.


Fiddle would deal 3270 base damage, plus 6.75 AP ratio to a single target in 5 seconds, which deals a total of 10 020 magical damage. His passive also means he has a little more MPen than any other mage, which gives him ever more of an edge.

That being said, assuming she hits her ult, hits with her E 9 times (it has a travel time, so you can't possibly hit it 10 times in 5 sec even at point blank range) and keeps her Q on for 5 sec, Cassiopeia would deal 2875 base damage, plus a 7.8 AP ratio, for a total of 10 675, which puts her OVER Fiddle in perfect circumstances (also remember that the Fiddle damage assumes he hits with Dark Wind 3 times the same target). That's without taking into account the -10 MR from Fiddle, but even vs targets with no MR, he would not deal more damage than indicated unless he gets help from Amumu or Soraka to shred their MR below 0.

Note that Karthus doesn't even come close to those 2 with his 6000 damage over 5 seconds to one target with 1000 AP. He does, however, have his MR shred on his wall, so that increases his dps of course.

Also, you have some fringe cases like Evelyn and Malzahar (6 warmogs target, for example) or Katarina (gets 5 kills in 5 seconds) who could top this off, but that's even more unlikely than hitting all your skillshots over 5 seconds.

Cassiopeia has the best burst, if you can land her Q.

Veigar

So um, nobody has hit on the actual answer. Pretty sure AP Kog with 1k AP will destroy.

Q: 260 + 700 = 960 (one shot in 5 sec)
W: 6 + 10 = 16% (approx 7 shots in 5 sec) = 112%
E: 260 + 700 = 960 (one shot in 5 sec)
R: 160 + 300 = 460 *2.25 (for hitting champs) = 1035 (5 shots in 5 sec) = 5175

total damage = 7095 + 112% of hp

i think that beats anybody else......