Katarina is an assasin melee mid champion. She doesn't use mana for her abilities. Her passive Voracity is just like Master Yi's passive, but once you get a kill it only cools it down for 15 seconds (pretty much affects her ultimate). In my opinion she is pretty over powered and not very hard to play, Riot recommended her.

Her Q-Bouncing Blades is a really good farm/harass ability. It hits up to 5 enemy units (Riot says it only hits four but it his 5). When it hits them it will mark them with a blade and your next auto attack/spell with deal bonus magic damage.
Katarina's W-Sinister Steel spins around with her knife and deals A.O.E or Area Of Effect magic damage, if hitting this on champion she will gain bonus movement speed for a short duration. This also is a really good farm/harass ability.
Moving to her E-Shunpo, is a good chase or getting away ability. She jumps behind any enemy or friendly unit. If it is an enemy unit it will deal a little bit of damage. You can not jump to any towers.
Her ultimate-R-Death Lotus is one of the best finishing moves. Katarina just starts throwing blades at the champion you have targeted, if you kill that champion you will start focusing another champion, it does this up to three champions. but once your passive kicks in and you get all three you will get it cooled down. This deals magic damage and reduces the enemies healing.

Farming is important on any champion! Not as much as important on Katarina as some other one's though. With farming you need to try and do this combo for each wave. Hit all of them one time q them then w them and you should have killed all but one, just auto attack it. If you can keep this by your tower but out of its range this will be super easy and you should be able to get ahead of your opponent easily.

In team fights Katarina needs to sit around and harass till your team initiates and gets them low then you can do this combo. E W Q R then if your w is off CD and your ultimate is done then you can W again and it should kill them depending on your Magic pen and their Magic Resist.

Pros: She can chase and get away easily with her E. She doesn't use mana for her abilities. She has boss cool down reduction. She is easy to play, and OP.


Cons: She can be harassed and killed easy. She is very squishy. She gets focused in team fights.



And that is all.

I hope this build helped you and my advice helped you!!! Trust me I am one of the best mids/Katarina players I know... Please share this guide with your friends. CYA