Hello everyone, this is cc10 and this is my first guide. I'll be writing about playing the omnipotent attack speed Kassadin. I apologize for the lack of coding, as I'm kinda new here.
Kassadin is usually played as an ap assassin who is capable of killing people and getting away quickly. This build is good - but not nearly as fun as the deadly Attack Speed Kassadin.
Now I'm writing this guide with few credentials besides the fact that I've won a lot of games using AS Kassadin, though to be fair quite a few of them were in the level 15-20's. I created this build while trolling a game and happened to end up dominating, assassinating enemy carries and putting out a highly impressive dps.
I don't play seriously enough to buy runes, even though I have almost 20k ip on both my real and lower level accounts. But I do have two pages, focused around some cheap quints that I picked up on sale during the winter. Kassadin's early game is pretty weak with this build compared to other champs, as he loses his mana quickly and does not have impressive base damage. I like to take health quints to let him survive until level 6, along with armor and mr to supplement that. As for the attack damage marks, they help Kassadin farm and do some extra damage, and since they are the only marks I have, I use them.
You could probably swap out the marks for magic pen, as it is the most useful late game stat for Kassadin.
I start off with boots and 3 health potions for survivability and mobility, as without his ult Kassadin is quite slow.
Early on you'll find that Kassadin loses his mana quickly if you spam his q. However, his w's built in passive allows you to regenerate mana by auto attacking. I like to start off with a quick stinger because it allows me to regain my mana in lane and then quickly spam it off again using the bonus cdr.
The next item, malady, focuses in on the attack speed aspect of the build. As most of your damage will eventually be magic (from turning on your w and attacking away), malady lets you shred your enemy's mr, making you hit harder - plus it does give you an additional 20 magic damage on top of your w.
At this point your main target should be enemy ap carries. Only attack when you know the enemy cannot respond with a massive burst. If an enemy wastes a spell or two, you can riftwalk in, silence, e, turn on your w and start smacking away. Not only will this do a surprising amount of damage, but due to your passive Void Stone, any damage mages throw at you will be reduced and converted into even more attack speed. Do not get greedy though - an ap carry can massacre you with a full burst once cooldowns have been refreshed. Riftwalk out before this happens.
Wit's End will improve your anti-mage capabilities even more, while also giving you bonus magic damage on your attacks. You can also swap this out for ionic spark if you aren't concerned about magic damage or you want to farm like crazy.
Bloodrazor ups your damage considerably. By this time, you should be able to launch quick attacks at enemy squishies and back out before they can kill you. This constant harass is aided by the fact that you basically have infinite mana. Bloodrazor lets you kill some tankier enemies, but remember you are an assassin still - though you can try to assassinate people at around 1/2 health now.
Your ending item is your choice. If you want survivability, grab Rylai's as it buffs your damage and gives you an additional slow. If you want sustain, grab a gunblade, as both your spells and attacks will heal you. An extra bit of burst doesn't hurt as well, but remember to use the active.
While laning, if you find that you are going b to often, don't hesitate to buy a quick vampiric scepter. This scythe will help you sustain yourself and allow you to farm freely.
This is pretty self explanatory. You want to start off with some early game damage on your q and e while taking a couple of points in w. From then on, you want to level your q and w side by side, making sure that you maintain a balance between assassin dps (your w), and in lane harassment (your q).
Laning phase might be hard, depending on who you're against. Try to use your q defensively against a champion with sustain, as they will most likely outlast you and leave you without mana if you spam. Against a more fragile champion, you can use your q offensively, but always save mana for a slow in case you need to escape from risky situations.
However, Kassadin is a very good farmer. His attack animation is very fast, and with my AD runes farming is a breeze. If you have to, use your q to farm as well, but make sure you save a bit of mana. You should never be holding onto all your mana, though, as you have little use for burst at this time and a method of regening it.
Mid game is where attack speed Kassadin gets interesting. With your ultimate, a stinger, and perhaps your malady, you can initiate hit and run tactics on enemy carries. Ult in, q, e, w a couple of hits, ult out. This can effectively lower their health and potentially force them out of lane. Farming should still be high priority, but try to nab a few kills here and there. You can gank quite well and getting kills isn't that hard with proper coordination.
Mid-late game you should be an anti-mage monster. Hide in bushes and wait for enemies to walk into melee range - then q,e,w and pound them until they are dead or your w expires. If you are ever in a dangerous situations just ult out.
Late game must be played like any other assassin, except you have far less burst than most assassins now. AS Kassadin will start to fall off as carries begin to outdmg you and people become tanky enough to counter you. Play like an opportunist, ulting in to kill 1/2 health carries and then ulting out.