Pros / Cons
[+] Two powerful nukes
[+] One of the nukes , is a silence
[+] And the other nuke is an AOE skill
[+] Relatively low Ulti cooldown
[+] Cool skins
[-] His really squishy through out the game
[-] People will be AIMING him down like a rat
[-] Mana hungry
[-] His a melee mage champ !
[-] Miss use any of his spells in battle and you're in trouble
Runes
Well i might don't wanna stress bout this part that much coz heyy , it is just to give you an advantage at early point of the game. Soo yeah it doesn't really matter which runes you give him but i just recommend you guys this runes on the build part.
Skill Sequence
I take a point in 
Null Sphere first since that is the only skill you're gonna have to take. Nothing else than that. Second skill will be 
Force Pulse. Now why that skill you say ? Simple. If you take a point to his second skill which is 
Nether Blade and picture this , sure you can spam all you want with it by using Null Sphere all the way. But it doesn't really gives you that dmg you want.
Besides , you can recover your lost mana back by using
runes
and
masteries
. If you take a point to his third skill which is Force Pulse now picture this , you now have two NUKES in your arsenal. Well despite that you need to charge up your Force Pulse first. That part , DON'T WORRY. The enemy will be SURE to use their skills once in a while. Trust me. Once you see it's fully charged by 6 charges , you'll see your 
Kassadin champ will have this slick "Void" Essence swirling around his body.
That's to tell you that it's ready to be release at those enemy champs ! For the enemy team , it's a Warning to them to be cautious. Once it's charged , they should have that fear to back away from you. And your job is to make that fear into a reality. Get up close to them and release it ! Release your Force Pulse first which is your E since it's an AOE nuke plus it slows anyone caught in the cone radius. Immediately after releasing you Force Pulse , release your Null Sphere to disable them from running away or even to counter back-fire to you. Coz if you aim your Null Sphere to them first , most probably they'll notice you're gonna release something to them. So don't give that chance to back out. Come in , slow em , then silence em ! If you have already released it all on them , and they still haven't died yet but on low health , BACK AWAY FIRST .
Trust me on this one , don't get greedy by just using your Nether Blade and auto attacking them , please by that time your silence on them is already up and they be able to counter you. Once you have your skills back up again you can repeat it. But of course you have to charge your Force Pulse first before going to your full combo. Once you reached level 6 , you have your 
Riftwalk up. And you know what this means ? I don't either :P... Joking heh.. It's time for you to get damn Aggressive ! Riftwalk right infront of their face and Null Sphere them ! Than backaway if you Force Pulse is not charged yet. If it is then release it as well. That should take out most of their health straight away.
The best combo ever without letting your enemy know that your Force Pulse is charged is when it is at level 4 charge. Why ? Coz it takes 6 charges to activate your Force Pulse. Yeah kinda sucks needing to charge it and all , but it's really deadly when used. Once it's level 4 charge , all you have to do now is Riftwalk in their faces Null Sphere them , and by that time your forcepulse is up ! What are you waiting for ? RELEASE THAT Force Pulse IN THEIR FACES !! They won't know that nasty little surprise could actually kill them.
I've realized that whenever i'm playing Kassadin and have my Force Pulse ready , the enemy seem to fear me alot. Coz they know by seeing that slick 'Void' essence swirling around me means trouble for them. And also it seems that they wait for me to use my Force Pulse on them so that they can counter. Well , if you use that nasty little trick on them , they won't even know that you can backfire them instantly !
Unique Skills
Hey before you guys say " Ahh this guy suck ! He doesn't even know what his talking bout !" Listen out to me first please. It may just win your next round instead of a failure. It doesn't hurt anyway to just READ RIGHT ? No ? Okay ... So please hear me out first , this is my very first build ofcoz. So gimme a break yeeeshhhh...
Team Work
Ha i need to stress on this part like hmm lets say ? ALOT ?! Yes .. What good for an assassin like Kassadin if his team doesn't even do a thing ?! Am i right ? I'm right.. Ha joking. Anyway. Kass neends a good team with good cooperation. Trust me. Kassadin really needs this. If not , Kass is just a sitting duck. He needs his team to completely distract the enemy team while they waste away their spells on his team , little do they know that Kassadin can just jump RIGHT IN and BURST EVERYONE DOWN and REPEAT. Am i not stressing this enough yet ?
Most of the time people won't be concentrating on him if his not to be seen by the enemy. Soooo. USE THAT CHANCE YOU KASS PLAYERS !! THEY DON'T KNOW YOU'RE THERE ! SO JUMP IN AND GET THEIR CARRIES !... Or might as well aim down their supports or especially the yummy ones ! CHAMPS WHO ARE ON LOW HEALTH AND RUNNING FOR THEIR LIFES !!! :D ..
Let's say you see a running 
Nidalee 
Pounce herself away and your right behind her , be smart to where she's going , coz that might just surprise her and take her down. Plus you don't have to worry charging your Force Pulse up , she's already doing that for you with her Pounce. As soon as you jump in , you have to jump right back out of there so that the enemy team won't aim you down like a rat.
Trust me , if they're pros , they know Kass's true potential if they don't take him down first. Oh and PLEASE don't jump in FIRST. Coz that's like uh umm... Suicide ? Yes... Your job is to hide in the shadows , unseen. Find the right time to jump in and punish them ! Burst down everyone you see on low health or who's trying to run away. But also don't be selfish using your powers to your own needs. Help out your team mate by silencing that pesky 
Katarina who's using her 
Death Lotus to finish off your carries. That one Null Sphere may just save your team mates life.
If you can help your team mates , than help. If you see there's no chance for him or her , or even for you in that matter. Than just back away. Trust me. One death is alot better than two. But well i can't blame you exactly if you haven't been dying that much but your team mates is , and apparently you're in a bad team where they kept insulting each other to what ever they do and all. Well that's where good cooperation comes right ? No ? Okay :( ...
Summary
Soo this is all then i can give you players who wana try out Kassadin or trying to Master him. So please do comment aite ! I really appreciate if you do so ! Tell me if i miss out anything ! See ye guys on the League ;)
#UPDATED !
[+] Finally made it more attractive ! I'm still learning !
[+] Information and builds are now more detailed :P
A BIG Thanks to JhoiJhoi's guide on how to make YOUR guide a better one !
Follow the link right here ! http://www.mobafire.com/league-of-legends/build/making-a-guide-101506
Build Guide
Discussion (7)
Malzahar players he is one of the void. And apparently if you read their lore correctly , 
Cho'Gath is also part of the void. One big family ? Ha ha ... No.. I'll be guiding you all the way with this guide , so please bear with me and my long , long talks.
first. To get that early mini burst of ap and also that mana regen. You should be spamming your 
.. Why that item you ask ?
right after that. It increases your ap and your burst. By this if the enemy team is aiming you , try not to buy any health items or armor aite ? 
or even
