Anyone got a good item build? Searched the other forum and didnt find much so i am here.

Start with Doran's Shield and a health pot.

Sorcerer's Boots
Haunting Guise
Rylai's Scepter
Void Staff
Abyssal Scepter
Banshee's Veil
Zhonya's

First 4 after Doran's Shield are pretty standard but you can choose any 2 out of the last 3. It's all about the magic penetration on Kat.

first off this build is slightly off after the recent change to armor and magic pen. I believe the flat magic penetration is calculated first then %. This means u dont want to mix the two because void staff wont be taking off alot of resist. Before the change u would keep Sorcerer's Boots, Haunting Guise and void staff because it went reduction, %, then flat penetration. I use this build:

dorans shield
Mercs boot
BF sword
Ryjals
void staff
banshees/Randuins omen if needed
zhonya

sell dorans when needed and the reason why i keep a bf sword as first major buy is for farming purposes and the nice boost to BB. U need gold and that little ****er helps out early mid game farming so much better then going straight AP and not having your BB hit for squat.

Kat isnt my main and i think i have only 90-100 games played between my 2 accounts....shaco was my guy but hes old news

All of Kat's damage comes from her ult during teamfights. It's way more efficient to put all your money into either AP or Damage instead of getting a BF sword and some AP. Getting a BF sword is 1850 gold that could be spent getting more AP. You could get two blasting wands (80 AP) and then some for the price of a single BF sword.

And even with the changes, you still need your Sorc boots and guise. 40 flat penetration is still too good to give up even if it makes your void staff slightly less effective.

Also, I respect your choice of Banshees Veil, but getting Omen on Kat is just ludicrous.

Rylais slows people with her ult, and with shunpo

magic pen pretty much rapes anyone who gets caught in your ult while they're slowed.

dorans shield + hp pot
mejai's soulstealer (i always rush this as AP kat because killing is easy) but usually get basic boots first.
sorc shoes or ninja tabi/merc treads depending on the team comp
giants belt into rylai's
if stacks are going great i'll go right to lich bane. if not i'll build either void staff for AP/pen or something.
zhonyas.

this way you do rush soulstealer, and by then you will not know how the game will play out if it will be good or not, but you have the chances on your side. you will almost always get the kills with your burst shunpo damage, great KSing skill DL to get last hits and cooldown reduction with kills/assists. even if you don't get the kills you'll get assists and still rack up the power.

keep in mind you're not dependent on building soulstealer for power, but lets be honest if you're shutting down katarina and her team to the point where she cannot get stacks, you'd be useless to the team even if you spent the money elsewhere...thats just how the champ works...either you will roflstomp or get gigglepwned.

if you are fortunate enough to build all items, you'll literally have like 800 AP and will not be able to be stopped. thats when people come here and scream OP OP

AP Item build: Don't play unless your low ELO. Nuff said...without ult she is lack luster... and thats going to happen when you have enemies with CC.

An AP build for Katarina will benefit from the same AP items that literally every other AP based build will benefit from.

I know people don't like to hear that, but it's true.

I usually get flamed at the beginning of the game for doing this but it works out 80% of the time.

I start with a Potion of Brilliance and 5 HP pots. Get shunpo to level two (at lvl 3) pop the pot and harass the **** out of thier team. I almost always get first blood (only if you have a good lane partner).

After that I go sorc boots, majais, Rylaighs(I butchered that spelling), zhonyas, void staff. Game tends to be over for me to worry about getting anything else.

I mix it up and buy brilliance pots throughout the game, usually after the majais and zhonyas. (for cooldowns and a little AP boost.)

EDIT: I forgot to add my rune page for Kat is pure Magic Pen/AP + HP Quints. It really does give you quite an edge.

i don't think elixir of brilliance adds much for it to be worth buying early game. you can already get good burst damage with level two shunpo and level one BB at level 3. trick is to survive what you'll eat while trying to burst them down.

basically i like to harass with BB and my lane partner until they are around half HP. if i can i'll just stick in bushes and bounce out to throw blades at them. i don't even worry about last hits much since i know i can get kills for my gold very easily.
once any champion is half hp to 1/3rd hp, you can kill them with shunpo/auto attack/ignite/BB and your partners help. if they are caught far up your lane, just run beside them until shunpo is back up and hit them again