Like your arguments as a whole, your math is really bad and missing so many points.
I mean i even challenged you with math and this is your best excuse what you can give?
Let me try to explain it to you, i will hold it simple, since you obviously dont understand the game mechanics off league of legends.
I wont even try to explain the stun to you, since evading it would be toot hard for you.
So the math for your "One shot"
Veigar Level 11 Ult does 375 + (1.0 AP) + (0.8 enemy ap)
Orianna for example now is level 11 with 400 AP (with 1295 Hp at level 11)
Veigar will have 500 like you said.
That means Veigar will do 375 + 500 +320 Damage = 1195
thats 1195 Damage but i see you couldnt even calculate this, even with your own conditions.
Now, do we now something that negates a percentage of the magic damage? yes we do? Jeah dude, it MR.
She has 30 MR without items (and dude, if oyu dont at leats get a grail or something you are stupid as shit).
So she gets 77% of the damage
1195 * 77% = 919 Damage.
WIth no Runes, no heal items like even a freaking
and not a single mr items from Oris side.
Soooo how excatly are 919 Damage one shot a mage with 1295 Health (no health items) ?
jeah, would still be 376 Health.
So its literally not possible under your condidtions.
EVEN IF IT WERE TRUE DAMAGE DUDE, and thats quite sad from you, to not being able to even know that...

So what your argument now? that its still insane Ap damage?
Jeah... nope, 673 Damage against somebody with no ap.
Fiddle by the way does 550 Damage per sec with 500Ap with its ult, so that would be after MR be, 2117.5 Damage in a huge Aoe.
You play fizz as i can see, not very well, but i will still take him for example:
Fizz 500 Ap = R = 635 Damage after MR. In a Aoe. And all your attacks do 20% more damage for 6 sec. With everything at level 2 and 500 ap that would be 146more damage if everything hits, so 781 Damage, against everyone, ap or not. (and i didnt even meantion the ability to evade 99% of all abilities ingame, THATS unfair)
So, my fiend, THIS IS MATH!!!
Thats probably why you never got a got degree or diploma in reallife because you cant even do the math ;D
I hope now you understand what i meant with
Also, because i KNOW you want to say he can: he CANT oneshot any decent player, if he can, then give me the math (you know, the school subject you probably failed)
and you failedi t again.
but if you can correct my math here im open for mistakes. could have been that i made a mistake, but i shouldnt be more than 1%-2% off.
Dont take this as an insult, i challenged you, you excepted, and now got your ass handed to you. now try the same if you can ;D