Hello, This is my first build at mobafire so dont go to hard on mee (if you have something add about my build, pleas leav a comment). Let mee intreduce you to "My way of playing katarina".

Ive seen Pure Ap builds at mobafire

Ive seen Pure Ad bulds at mobafire

Ive seen Hybrid builds at moba fire

But none exactly like my build, so i thaught that i'll share it with you since it turned out to work pretty awsome :)

Before you leav the platform for some heavy ***kicking you should pick upp a pair of, Boots of Speed (for some easy harras) You DONT NEED more hp in LvL1, the runes gives you ~610 Hp W/o item or mastery, and dont forgett to add the 3 Health pots.

Now, skill your lvl 1 Bouncing blade and last hit minions, and use your movement speed to harras with the blade (bee sure you arent to far behind theyr minion line (they make op dmg when you are lvl 1 xD )

You shouldent need to recall before you can afford Sorcere's boots and maybe a Amp Tome/giants belt.

(its rly good to use shunpo/blade/run as harras if you oponents arent extreamly lethal)

Ok, this is when you make them feel totaly hopeless, at Lvl 9 your Bouncing blade rly should bee at lvl 5 (the key to theyr surrender), Use the blade to harras as soon as its off Cd Press W/Q/target Bounce Bounce Bounce x3-4, MISS oh they recalled cuz low hp! Lets gank lanes or hit tower.

Mee my self always trying to get mid with katarina to get lvl 5 baldes as soon as possible.
When you go mid (Pray to the gods you dont meet morde) harras ALL THE TIME Shunpo/Blade/run/blade/blade, Spam the blade all the time and move alot, and last hit minions ofc. When your Blade are at lvl5 they WILL smell the Defeat cause of your OP harras. Take theyr life down to 30-40% wich usualy goes pretty fast, (if they recall, you Farm or gank) If they stay well KILL THEM (if you have Ryalis) W / Balde / Shunpo / Ulti / (should bee dead) / Blade / Shunpo/Ignite. ( And ofc bee realy carefull if its 1 miss or 1 jungler) remember, you can Shunpo to (Minions/champs/wards, almost everything exept for turrets for a clean escape).

Now you should have Sorcere's Boots, Ryalis and maby hextex gunblade and some rly heavy dmg.
Now as well, just harras/gank/push with your team.

This is the most important thing to think about as katarina
If your tank initiates a team that have heavy Cc Amumu(stun)/Shen(taunt)/Sion(stun), etc wait until you see that shen for example taunts someone until you jump into fight and throw ulti. This is cause katarinas ulti is extremly easy to interupt with (silence/stun/taunt, etc so use it wisely)

Otherwise its like playing with any other champ late game, Alone --> dead, STAY WITH TEAM, gank, Take dragon/baron as soon as they respawn put out wards.

Sorcere's Boots:

Just a must imo, Ulti makes Flat Dmg+ap+ad (not 100% ofc) As magic Dmg + the Magic dmg on shunpo + well you know it.


Ryalis:
The key item to katarina Cause, Nice Ap, Awsome Hp, PPPPpPPpENTA SLOW!

Hextec GunBlade
humm Hybrid? Hummm ad/ap? Humm Hextec! Great item, it just is.

The Blood thirster:
Attack Damage? Taste that Blade sucker! + awsome for ulti Dmg.

Rabadons Deathcap
Riot Games gave uss this OP item as a gift from above (boosts your ap Skyhigh)

Banshees Viel
You can Ofc get this item earlyer ( you must ) if theyr team have a good Cc

Pros:

can carry the whole team to victory of feeded.

Realy FUN to play

Great Survivability

With Ryalis you can save a team mates *** even at low hp, (bouncing blade minion) bouncing on the hunters (multi slow)

Spamable Ulti ( 15 Sec Cdr for assist or kill )


Cons

Focused

realy easy to interupt ulti

Can't think of anything else ^^

Now i cant realy think of anything more important to share at this moment.

PLEAS: If you have any tip or opinion (since im new here) Leav a comment.

I will add more later for sure.

Sry for my english, its not my main language but i'll hope you understand what im trying to say :P

Some of my games with kata Atm have 12 Wins 2 Lose in ranked