katarina is high risk hgh dmg champion remember it all time when u play her
u can survive a lot whit small hp doing crazy things think of katarina like of akali
Pros:
She doesn't use mana.
Highest damage output in the game. (Her ulti does 1700 AOE damage at level 16 [whit abaut 500 ap])
Can carry a team if played right.
Built in ignite.

Cons:
Vulnerable to crowd control abilities.
Hard to master.
needs to be melee range to do maximum dmg
its hard to play if u loved old kata
katarina is cauntered easely by high dmg tank

well i dont have what to say i have just standart kata masteries

I didint say in items but u can buy hourglass or abysal scepter and dont buy deathfire grasp or
void staff

http://i1144.photobucket.com/albums/o498/AnnikaNewby/katpassive.png
Extremely good Passive allows her to dive in to finish people then escape or dive , get a kill , dive someone else get another kill and snowball
http://i1144.photobucket.com/albums/o498/AnnikaNewby/katq.png
his is used for farming , and putting the mark on people. use it on a wave of creeps and then use W and bam amazing farm :) use this in lane for slight poke and sometimes bigger whit q e w combo
http://i1144.photobucket.com/albums/o498/AnnikaNewby/katw.png
Kats new Ability!!! Wow haha i love it! Low CD, Clears creep waves , nice aoe , good damage! I love it also it looks sweet! Haha :)! and speed boost to chase and escape! Love it!
http://i1144.photobucket.com/albums/o498/AnnikaNewby/kate.png
this skill is used to ks the **** from team and to catch or run away
http://i1144.photobucket.com/albums/o498/AnnikaNewby/katr.png
well its old kata ulti just u do dmg in 2 seconds and i think ap ratio is higher now

in late game q just kill a wawe but mid game use q then w combo