For you trolls out there, I've got a Kayn build for you.

The Shadow Assassin form of Kayn causes him to deal 12-44% of his damage output as bonus magic damage.

Initially, I thought this was just attacks, but it actually extends to his abilities and even his items.

So, naturally, I thought one thing: how far can I take this?

The answer is "Too goddamn far".

Well, here it is: AP Kayn.

He may not have any AP Ratios, but the AP Ratios on his items are getting amped quite a bit.

Here's the build.

Hybid pen marks, MR glyphs, Armor or HP/Level Seals, one AD and two AS Glyphs.

9/21/0, Thunderlords.

with a

Go mid, because if this build goes wrong you'll basically be running it down that lane anyways, so it's best to have a head start.

Rush the gunblade. You have no AP scaling, so this is the best thing for you. The revolver damage is high, and the cutlass gives you enough AD to do damage early game.

After that, your sole purpose is to get your Shadow Assassin form as quickly as humanly possible. Ranged champions are your preference, obviously. Melee's are fine too, but you have to wait four minutes to get your Shadow Assassin form if you hunt them.

Grab a sheen first, and then a desperation stinger if you haven't gotten enough items yet. Now, finish your Lich Bane and pick up a Ludens before that item would be useless.

Round out the build with the Nashors, because it scales with AP, and Deathcap, because we need AP for this build to "work".

-_-

Now, the fun bit: numbers.

Kayn at level 18 amps his damage by 44%.

Your (offensive) stats are as follows.

1.31 Attack Speed (Note: I forgot to take the AS runes into account, so your AS would be slightly higher than this. Not a huge difference, but still) 150 AD (42 bonus) 688 AP

You open by sneaking to them with Shadowstep, and then doing gunblade+Q+W+Autos+R+Q+Autos+W+Auto.

Gunblade does 360 (+0.432 AP) damage (658 total).

Q does 389 (+1.82 bonus AD) damage (468 total) if you hit both instances.

Ludens does 144 (+.144 AP) damage (243 total).

W does 374 (+1.728 bonus AD) damage (446 total).

At this point, you have about two seconds left of damage amp, so we can just spam autos.

1.31 attacks per second is equal to 0.65 seconds per attack, so we can do three.

The attacks themselves deal (3(1.44 AD)) physical damage, 648 total.

The lich bane proc deals 116 + (.72 AP) damage, 611 total.

The three Nashors procs deal 3(22+(.216 AP)) damage, 512 total.

We let the amp wear off, R isn't amped. It deals 350 (+1.1 bonus AD) damage, 396 total.

We wait the full 2.5 seconds in our ultimate.

The Q out of trespass does 468 again.

We do two autos.

Lich bane does 611 again, the attacks do 432, the Nashors does 341 damage.

W does 374 again.

The final auto does 216 plus Lichbane's 611 again and Nashors 221.

We get two sorcery procs in this, for an extra 72 damage.

This all totals out to 7,328 pre-mitigation damage over a period of 8.5 seconds if you did it optimally.

If you see a squishy, you just teleport behind them and "nothing personal, kid" them.

(Edit: ah shit. I forgot to take into account Masteries. Those things give you a lot of damage, so that would probably add a few hundred damage to the total. Thing is, I'd have to re-do a lot of math, so...)

-_-

Now, what's the point of all this?

The build is impractical and does almost nothing until you are both level 18 and full build.

Well, the point of AP Kayn isn't that it's good.

The point of AP Kayn is that HOLY SHIT, POWER CREEP.

Riot, this guy has NO AP SCALING, yet I can build him full AP, and deal damage in the thousands.

If this is how much damage he does with no ratios, I am seriously afraid to see his numbers with an ACTUAL build.