Hi! Here is the Story of Kassadin:

There is a place between dimensions and between worlds. To some it is known as the Outside, to others it is the Unknown. To most, however, it is called the Void. Despite its name, the Void is not an empty place, but rather the home of unspeakable things, horrors not meant for minds of men. Though such knowledge is lost in modern times, there are those who have unwittingly discovered what lies beyond, and they have been unable to turn away. Kassadin is such a creature. He was once a man forced to look upon the face of the Void and forever changed by what he saw. Once a seeker of forbidden knowledge, he discovered that what he sought was something else entirely. He is one of the few that has found his way to forgotten Icathia and lived to tell the tale, following the scant breadcrumbs hidden in ancient texts.

Within a decaying cyclopean city, Kassadin found secrets of the kind that he will never share - secrets that made him quake with fear at the visions of things to come that were thrust upon him. The power of the place threatened to consume him forever, but Kassadin took the only route available to him in order to survive - he let the Void inside him. Miraculously, he was able to overcome the alien urges that went with it, and he emerged as something more than human. Though a part of him died that day, he knows that he must protect Valoran from the things scratching at the door, waiting to get in and visit their torments upon the world. They are only one step away... something to which the appearance of the abomination known as Cho'Gath attests.

If you look upon the Void, you can't put it behind you. If you look upon Kassadin, he is probably already there.

Hi! This is my 3rd Build! I tried out Kassadin, because i saw NinjAChurch playing it and he simply OWNED everyone. I tried out kassadin with the recommended build, and i ended with, 2-2-5 (i though i picked the worst champion ever) i tried my own build, and i had 20-2-18.
I do scores like this nowadays.

Void Stone (Passive): Kassadin takes 15% reduced magic damage and transforms this damage into bonus attack speed.

Null Sphere: Kassadin fires an ethereal bolt of void energy, dealing damage and silencing the target for a duration.
Kassadin fires a void bolt, dealing 80/130/180/230/280 (+0.7) magic damage and silencing the target for 1/1.4/1.8/2.2/2.6 second(s).

Cost
70/80/90/100/110 Mana
Range
700

Nether Blade: Passive: Kassadin's basic attacks restore Mana. The Mana restored is tripled against enemy champions. Active: Kassadin's basic attacks deal additional magic damage.
Passive: Kassadin's basic attacks draw energy from the void, restoring 8/11/14/17/20 Mana each hit. If the target is an enemy champion, the Mana restored is tripled to 24/33/42/51/60.

Active: Kassadin charges his nether blade for 5/5/5/5/5 seconds causing his basic attacks to deal an additional 20/30/40/50/60 (+0.15) magic damage.

Cost
25/25/25/25/25 Mana
Range
1

Force Pulse: Kassadin draws energy from spells cast in his vicinity. Upon charging up, Kassadin can use Force Pulse to damage and slow enemies in a cone in front of him.
Kassadin draws energy from spells cast in his vicinity, gaining a charge whenever a spell is cast near him. Upon reaching 6 charges, Kassadin can use Force Pulse to deal 60/115/170/225/280 (+0.7) magic damage and slow enemies by 30/35/40/45/50% for 3 seconds in a cone in front of him.

Cost
80/80/80/80/80 Mana
Range
400

RiftWalk : Kassadin teleports to a nearby location dealing damage to nearby enemy units. Additionally, multiple Riftwalks in a short period of time cause them to cost additional Mana and deal additional damage.
Kassadin teleports to a nearby location dealing 60/90/120 (+0.5) magic damage to surrounding enemy units. Additionally, each subsequent Riftwalk within the next 7 seconds costs 100/100/100 additional Mana and deals 60/90/120 additional damage.

Cost
100/100/100 Mana
Range
10000

Pros:
-Awesome Nuker Mid/Late Game.
-Rift Walk makes you unable to cath.
-Rift Walk Make your enemies unable to get away.
-Can silence enemies.

Cons:
-Very Squishy in Whole game.
-Mana Dependent.
-Item Dependent.
-Hard to master.

My masteries are 9/0/21. Nothing to say.

I start out with a . I pwn some minions and i go for Firstblood. when i recall, i buy , and Health Potion x2, and 1 Mana Potion. After kill more minion and pwn enemy champions, i recall, and start Archangel's Staff. When i have enough gold, i finish my Archangel, and start Lich Bane and finish Lich Bane.
And then Void Staff, and Rabadon's Deathcap.

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Your skill combo is: Null Sphere ---> Rift Walk ---> Nether Blade ---> Force Pulse ---> Null Sphere ---> Riftwalk...
if you couldnt kill him with first 4 spell, then repeat, Null Sphere, Force Pulse, Rift Walk.

Me Use:
: Ignite O.o My favoourite Summoner spell. You can kill the lucky enemies who try to escape with 50 hp.

: I know i already have a blink, but at early game, you have no escapes and you are very squishy.

Good:

: You can defend your lane/Attack enemy lane.

: Good for Early game, and Good for Baiting.

For Runes, I use:

9x Greater Mark of Insight x9
5x Greater Mark of Potency x5
9x Greater Seal of Potency x9
5x Greater Glyph of Insight x5
4x Greater Glyph of Potency x4
3x Greater Quintessence of Potency x3

Thank you for reading!
I hope you liked the guide.
The Guide made by me, Raven843.
If you want, you can add me to friends: Raven843 (EU Server, Nordic, East)
You Can Check my other builds too: Brand Guide Made By Raven843

Morgana Build Made by Raven843

All Credits Goes to me, Raven843. Dont copy my Guide without my Permission!

Now go and pwn some ***es !