Gather round, children, gather round-- there is much to discuss. Since his release, two things have been accepted about Kassadin:

1. He's a (mediocre and situational) burst mage assassin.
2. His W, Nether Blade, is barely useful for its passive and was certainly designed by accident by competent, professional developers (and should always be maxed last, because it's useless.)

Now, why do people believe these things? Because they're stupid, and I hate them. They cry in tongues and sacrifice lambs to the Metagame and when the Metagame says Kass is a mediocre and situational burst mage assassin, you malformed infants obey.

BUT THAT'S WRONG, IDIOT. STOP IT. TAKE A BATH.

Today, we are going to discuss Melee DPS Kassadin. Melee DPS Kassadin will put out a forest fire by bludgeoning it with a glowing sword. Melee DPS Kassadin will autoattack Lee Sin to death without expecting or receiving any consequences. Melee DPS Kassadin is your real father, and your real father's father.

HOW DOES IT WORK, DOC?
You get mostly defensive runes and Attack Speed marks, and go 20-10 in your masteries (if you don't get Spellsword on Kassadin, I swear to @Ezreal I will find you and euthanize you like a sick dog.) The idea is to get enough defense to not evaporate in teamfights, while stacking as much piss and vinegar into your on-hit melee damage as possible.

-You'll be defending yourself with Wit's End and Rod of Ages. If you're too awful to survive with just that (spoiler: you are, and I'm ashamed of you,) then grab another RoA or Frozen Heart. Something with lots of mana.

-You'll be doing damage with Berzerker's greaves, W (Nether Blade,) Wit's End, Muramana, Malady, RoA, and Rabadon. Before we wade into the insanity of your on-hit effects, remember that Muramana puts you around 195 AD before we add on all the good parts. Wit's End and Malady bring W's base damage up to 147, while Malady and Spellsword bring W's AP scaling up to 45%. RoA and Rabadon give you around 200 ap, which turns into around 90 bonus magic damage. Now activate W and add Muramana's toggle onto that, and you're doing more damage to your enemies than the gutter behind Wendy's is doing to your mother's knees.

But you still max W last, right? Because the Metagame says it's useless?
What did the doctors call your syndrome? It's not contagious, is it? Nether Blade is Kassadin's BEST ABILITY. Its passive means being OOM lasts roughly one second and its active effect lets you ramp up your melee damage FAST if you max it early (which you will do from this point forward.) It also gives you an extra on-hit effect which blends extremely well with on-hit items (as I explained above-- go read it again before your blank, reptilian brain forgets it, you awful mistake.) Maxing W first is also not something your idiot opponent is expecting, because your idiot opponent doesn't know how to play Kassadin correctly. After maxing W, max Q because Q is mind-blowingly awesome against literally everyone. I would say it's not as effective against auto-attack heavy carries, but you can out-DPS Master Yi so who cares.

What's the build order, sensei?
Boots and three pots -> Tear of the Goddess -> Wit's End (get the MR first, not recurve, you dunce) -> Berzerker's Greaves -> Manamune -> Rod of Ages -> Malady -> Rabadon's Deathcap.

Wait, why get Deathcap LAST on an AP champ?
Because Melee DPS Kassadin can win a game with the other five items anyway. If the game drags on long enough for you to buy Deathcap, your opponents will then see a sixth item in your inventory called "TAKE. THE. HINT."

Is there anything else I should know?
Not off the top of my head, but I'm sure you lepers will need more help. Feel free to ask any questions that your vacant skulls can string into a sentence, and I'll be happy to help.

Remember that playing Melee DPS Kassadin will earn you the esteem and envy of your peers, but will never extinguish my searing contempt for all of you. While I hate you all as a group, each of you is a unique snowflake with one-of-a-kind traits that make me hate you, specifically. Inquire, and I will be happy to elaborate.

TL;DR:
You're on a message board for a video game you take entirely too seriously. Your time is not valuable. Scroll back up there and read it the right way this time, you simpering parasite.

I lol'ed at almost everything. Ok. I'm going to inquire.
I have three questions for you.
1. What the hell kind of noobs were you playing that put you on that mountain that you are on?
2. Why can't I just harass you into oblivion while you sit under that beautiful turret of yours and beg for mercy because you can't get any CS?
3. Why do you hate me? I would enjoy to hear what kind of traits incur such blistering ferocity and hatred to compel you to make a post like this.

Well, Guy on a bus, first let me congratulate you on not having an anime refence and a random string of numbers as a username. That's a rare skill you have, there.
1. Virtually the entire LoL fanbase. Turns out, paying someone to bring you up to 1400 elo and playing leblanc, mord, vlad, teemo, or talon mid doesn't help you grasp the majesty of Melee DPS Kassadin.
2. Probably because I keep silencing, slowing, and scalping you on sight instead of trying to keep my distance with a melee-focused build. That generally only works on burst-mage Kassadin, the players of which are wrong and unwanted by their family.
3. Your first failure is believing I care enough about you to know what to hate. But please, we're all friends here! Introduce yourself. What champs do you main? Where does your username come from? Were you inspired by the fact that you're as inconsequential as the unwashed nobodies taking the bus to Wal-Mart?

I think you are missing the fact that you are a melee character, and melee characters are easily harassed.

Now, a little about myself: I don't main anybody. I tend to be an all around type of person because I believe in a saying: Know your enemy like you know yourself. (Knowledge is also half the battle.) My username was inspired by my bus ride across the United States about 2 weeks ago. It's a real eye opening experience, you should try it.

this is a completely new idea and ive never heard of it before

Only a few issues my excessively agressive child. First of all, any on hit magic damage build requires that you invest in mpen. Malady is not going to cut it. Without mpen you will find that your ability to DPS is stymied.

Your .3 ratio on nether blades will only last you 5 out of 12 seconds, furthermore, since you are skimping on mpen, and building ap late the actual damage that you ar getting from the ability is going to be gimped quite severely.

You ar light on defenses. You have chosen a sustained damage format but you have no actual tankiness aside from the RoA and whatever MR you manage to scrounge from wits end. Any ADC or bruiser will butcher you, they have kits that are better adapted to sustained damage. Since you are lacking burst you are going to find it difficult to finish your average AP before they can combo you. Even if they aren't a DPS monster like brand or leblanc most AP mids will be able to bully you on farm early, establish a gold advantage and turn that into a face melting when you finally get to six and start applying the first serious harass that you have ever applied.

I would love to see what lane you want to Play with this build. It actually might work as a jungle if you did some work on it, but it won't work top as I would love to see how riven feels about you jumping in her face. Or how you would survive a lane against yorick mori. In mid you are going to get harassed and then exploded.

Wow Sodium. I think you elaborated very nicely on what I said. The whole thing is very elegant and clean.

http://www.youtube.com/watch?v=9x7yERLuHho

All you need to know

Melee DPS Kassadin goes mid only, for starters. I'm almost impressed by your theorycrafting idiocy, but there's a few things that confuse me.

1. You seem to be implying that I thought up this build without playing it, over and over, then deciding to share with the unwashed masses with no experience. Did you bounce when your mom dropped you as an infant?

2. You say "Any ADC or Bruiser will butcher" me, but I tend to punch their blood out too fast for that. Riftwalk means their ranged harass doesn't matter. Stop imagining what this build plays like and GO PLAY IT, YOU SQUEALING COLD SORE.

3. You bring up a valid point with MagPen, which this build lacks. I intended to include some, and there's room to add it in... but I've been liquifying non-tanks too easily to bother with it so far. If you want Magic Pen, get some and shut up.

4. Not tanky enough? You mean "Not a tank." High-ish HP and early magic resist actually does wonders for you against mages all game long, as long as you don't sit around and let them harass you. Just wait until they're alone or out of position, then jump them as fast as possible. They will die. If you die too, keep practicing the build until you stop disappointing your family.

5. Kassadin's gap-closer -> silence combo puts solo mid champs in awful situations (like he's, you know, specifically designed to. Idiot.) On top of that, W's passive means you can afford to lay down your own harass (with silence!) and rushing tear means you really, really should spam Q.

Now man up like your stepdad never taught you to, play the build until you get good with Kassadin, then come back and thank me for rescuing you from your bleak, Melee DPS Kassadin-free life.

Good lord, you are a pioneer of cutting-edge retarded mistakes. Did you slap that together yourself with MS Paint and Windows movie maker? Wait, of course you didn't. Guessing from your rancid embarassment of a post in an otherwise intellectual (lol not really) thread, you must have an IQ lower than your age and you couldn't be a day over 15. Congratulations on figuring out how typing works, and not forgetting how to breathe so far; but if I may make a suggestion, I'd say go ahead and forget how to do both of those. Much obliged, you writhing pus-filled hooker dropping.