I know everything except the build is pretty much s***, so I've decided to remove everything except the build. I could make it a lot better but I'm too lazy.

Good guide,but to max her damage early laning phase you want to get her Bouncing Blades to Level 3 then maxing her Sinister Steel is a lot better then leaving it at Level 1 then maxing Sinister Steel

well for starters its got the whole "wall of text" thang going on. I also don't think you should put the majority of your item info in the note tabs, as I believe they are for super-quick summaries(like 1 or 2 sentences).
And as was said before, not enough overall info, however what is here is mostly correct.
Work on it and it could be good.

At least it's not one of those other Katarina guides with completely ******ed items. Still awfully incomplete, however, so the downvote stays until it gets fixed.

Cheatsheet is okay. Here's where you mess up:
Elixir start is stupidity on a stick.
Sunfire Cape is a no-no.
Abyssal Scepter should almost always be core, Zhonya's is situational.
Liandry's is definitely not core, should also be situational.

Same goes for your runes and masteries. Good, but could be better:
Butcher is useless.
I don't understand the Quintessence of Movement Speed. I guess it's to compensate for the lack of boots start? Even then I think that rune slot would be much better fitted with more MPen/AP.

Now, on to the actual guide...it's pitiful. This is seriously skimming the surface of both barebones and superfluous at the same time. Literally, your entire rune section is a sentence. You skills section doesn't even go over all the skills.

If I didn't have a strict rule of not downvoting other katarina guides (people would assume bad things), I would downvote this. Let this be a warning. Archive this and complete the guide.

About the Item-section, I know it lacks a lot of information, but I'm just too lazy to add more, but I'll try to change it as soon as possible. About the chasing combo, I ment to do it like you mentioned, sinister steel then Bouncing Blades, but I guess I wasn't paying much attention to what I wrote. Next time you look at the guide it should've been changed, thank you for pointing it out.

Oh, and btw, thank you for the first rating =D

Well, I generally like this guide, but it would be nice if you would more infos to the Item-section. As example why you choosed the core this way or what you should do to addept to certain situations. Also the chasing combo seams a very bit weird. Your W gives you movementspeed, so why not use it before your Q to chase better if they flash? ^^

Okay, just becasue i had some time, and cause your build needs alot of work. i will help you out.

let me first talk about your items. If you want that much sustain from the start. Change it too Crystalline Flask plus 3x Health Potion. This is a way cheaper way to go cause you can recharge the Crystalline Flask when you go back to base. The wards are to expensive to buy that early in game. just get them when you go back the first time. Next buy Boots before the Haunting Guise and then build the boots into Sorcerer's Shoes. The Abyssal Mask after that is fine by me. I personally would build Rylai's Crystal Scepter and Liandry's Torment Cause they work really well together. after the abbysal you should go for Rabadon's Deathcap and make the Void Staff optional when they are building alot of MR (magic resist). replace the liandry's with it.

Thats all for now. for the rest of the build. just go more in depth and use the build guides i linked in my previous comment. Look at it this way. you are trying to teach a champion to someone that never played Katarina. So explain everything you can think of.

good lcuk with that. if you need any help contact me if you like.

Let me be the first to say some things. You will have to work on making your build more appealing to read. Cause when i go through your build it's not screaming to me: "HE YOU!! read this, its fun and interesting and you will learn everything about katarina"

Your build still needs a lot of work. Use the help guides that are available on this site

here are the links:
How to make a guide

BBcode guide

Use these and improve your build with it. then i will come back and take a look at your way of playing katarina