Sorry, but I have to downvote this. This guide is very generic. There is nothing unique about it. Everything in this guide and more can be found on just about every other Kat build on this site. Maybe you should give some tips and tricks. For instance, my issue with the build order was getting gunblade, rylai's, then rabadon's. My personal opinion is that I side with TiensiNoAkuma's guide that you shouldn't get Rylai's. In his guide, he laid out a huge table argument defending his position against Rylai's. I'd like to know how you make enough gold to get all 3 items consistently. Some of your farming and ganking tips would be good for this guide.
Your vs champions is a good idea, but it needs to be expanded a lot.

You are incorrect sir. Just... Just no. you get Bouncing Blades first. That is a definite. It's a much better farming tool and it's better for harrass. Shunpo should under no circumstances be taken first. it should be Q,E,Q,W,Q,R then prioritize as you said. Bouncing Blades Is so much more useful early game.

Don't get Bouncing Blades first, especially when you are AP Katarina. It should start as E,Q,E,W,E,R, then prioritise > and . Everything else is okay, I'll give you a +1 for this.

Gahhh... I feel sorry for you for getting trolled honestly. so 'i guess what I'm saying is that it isn't bad and giving you a +1 wouldn't hurt... +1

turn on comment to vote, you got two down votes and nobody commented saying why

It's a good start. You need to build on it though. Add in situational items, alternate rune choices, how to play her in each lane and at each stage in the game, how to use her in team fights, how to escape with her, how to tower dive with her, how to etc... The items are nice although not as good as they could be (I prefer void staff over rylai's as you already have a slow in the form of hextech's active) You don't need to be any tankier than you are with zohnya's. And if you do then that's where the situational items comes in. Your life steal/spell vamp from hextech should be enough to keep you alive though. Anyway just my two cents. Good start. P.M. me when you've put in some more information.

I like your guide, but i also must agree that it is too short. Try adding more pictures, coding, or maybe just more detail and explanations. I might also suggest putting some situational items or other viable items.

i like it ^_-

but i feel like the guide is too small try to put some images [katarina is beautiful, easy to find lovely pictures.]