Kassadin is the most banned champion in ranked solo queue for a very good reason. He dominates almost ever ap carry if he is played correctly he got amazing burst, mobility, a long silence, a flash thats almost rdy all the time and he snowballs better than any other ap char in the game. Just the combination of his Null sphere plus Force pulls can take half the hp of your enemy in lane and with the silence your enemy is unabe to even start trading.

The runes i choose seem very strange for an ap carry because you would expect an ap carry to go ap runes but i dont feel like kassadin needs that. He does so much dmg just with his base dmg which makes dmg no problem at all for kassadin player so you can go much more tanky with your runes . This is good especally against good players who mid try to poke you from long range and keep you on distance. So health regen helps you if you got hit by some attacks of any kind and Mage resist reduces dmg hard as well.

As i said before kassa got very Much dmg without even getting dmg imtes early on so he could go deffense masteries as well . But i dont think that with my item and rune choices thats need especally cause of the great options to boost dmg in the offense tree. Ofc kassa needs longer neutral buff duration cause kassa with blue buff is the biggest threat you can think of in solo queue .

For items i start with DOrans shield for several reasons. First to say oyu can ofc start with dorans ring or boots and pots and still carry the game but with even more health regen and more health you will be able to stay in lane for ever . Whats very important to say as well is that some good teasm might try to counter you by moving there ad carry to mid lane and the armor of dorans shield will be very helpfull to deal with that and against ad jungler ganks as well ofc.

With skills i start with Null sphere simply for lvl 1 figths and harrasment in lane after that i take 1 point in nether blade to regenerate some mana by hitting minions after that i max null sphere and force pulls together so the combination deals maximum damage to my enemy and ofc i take a point in my ultimate when ever possible.

Summoners are always dicsusable i think ignite is definitly needed flash maybe not but its just a nice to have when you are in bad spot and you need to get away or chase abn enemy that just barely espacaped if you feel like you dont need that you can go teleport or even exhaust as well heal might be viable too.

Pros:
-insane burst
-sustain ability (with this build)
-flash almost ever rdy
-almost not gankable
-stackable dmg on ultimate

Cons:
-banned almost ever
-only 2 real dmg spells so no sustain dmg like ryze or fizz

Just dont jungle kassa :D

In tf you should always stand back and if you got the mana and blue buff stack your ultimate when fight starts you come in adn burst down high priority targets get out wait for burst and get in again.

Kassa is really hard to farm with so you need to last hit as kassa is melee thats ofc not too nice against other casters who are mostly ranged. IF you get attacked farming just remember to have your burst rdy and pull out all the time.

While laning always q to harras and q e when both rdy you can hit minions to regen mana wiht your w but try to not miss last hits through this. Whne you get your ultimate its even easier to harras because your enemy cant stay out of range you can just flash in burst walk away.

Try to get gp banned when you play kassa because he is insane counter to kassa you have no cahnce at all against a gp no matter how good you are so jsut dont try you must switch if you area gainst gp in mid lane.