This is my first attempt to write a guide for anything.

I'm Kgmck177 and I've played Katarina as a main champion for almost 3 years now. After her rework and several tweaks to her ultimate I noticed that Katarina was much squishier than before, due to Bouncing Blade (Q) becoming her main damage source and Shunpo (E) being nerfed damage wise. This led to Katarina no longer using Shunpo as a finisher and being able to Shunpo out of the fight again immediately after. While this has worked out for the better as Katarina, when fed became ridiculously overpowered even without her ultimate, now relies on her ultimate a bit too much as it can be interrupted by so many champions and is her primary source of damage. I've listed my normal Burst Build for people who do not want to look at my new controversial take on Katarina however feel free to keep reading.

Pros
+ Excellent burst damage.
+ Great for assassinating carries in a teamfight.
+ Good ranged harass.
+ Good farming potential.
+ Is very mobile.
+ Very sexy.

Cons
+ Very squishy.
+ Almost always interrupted.
+ Damage is low pre-level 6.
+ Is usually focused down first or second in a team fight.
+ Very item reliant.
+ Hard CC's (stuns/snares/suppress) will still leave you dead.

This new build's main point is to try and give Katarina both sustainability and consistent damage output without sacrificing too much of her normal burst damage from sheer AP. The two core items from this build are Malady and Nashor's Tooth. With these two items and Spellblade Katarina's basic attacks gain a huge damage buff and synergize well together. Katarina gains some durability from Liandry's Torment however this can be swapped for Rylai's Crystal Scepter if you prefer more health and a better chase/escape tool over damage. Hextech Gunblade is the item that completes this new set, as many Katarina players will build this anyway over Will of the Ancients, thinking that Katarina can make use of the attack damage even with her slow attack speed. However this new build takes advantage of something normally overlooked: Katarina's high base attack damage.

Using this build a skilled Katarina player can overcome the normally brutal Kassadin or possibly even Talon in a head to head fight, as you longer rely entirely on your abilities that these champions can and will silence. Your main focus will be to utilize the much lower cooldowns to mark the enemy with your Q and consume the mark with your autoattacks while your lifesteal and spellvamp keep you healthy. Shunpo is still used as a positioning tool or can be saved for the middle of a fight to dodge some of those nasty skillshots. Sinister Steel fills the role of AoE still but shouldn't be used in a one on one fight over your autoattacks, instead save it for farming marked minions or for when you jump into a large teamfight as it will provide more health from spellvamp when it hits around 3 or more targets.

Katarina's basic attacks can hit fairly hard for a champion with no AD boosting items or masteries, especially against towers. Using Malady is the core of this build as not only will you hit faster your AP, which is still fairly high (around 350-400), will make you deal increasing damage as Malady applies a stacking MR debuff to your enemy, which Katarina's hard counters like Kassadin and Talon cannot silence.

Though I did not take screenshots to show my results (as at the time I was simply ****ing around), I found that I had stumbled onto something that could be worthwhile and kept a running tally of how many games that I kept a decent score on for an AP Carry. While this may be due to the enemy players being rubbish or my teammates carrying the game, I still feel that this is a valid play style.

Out of 30 games with this style, Katarina showed good statistics for the average AP Carry in over 25 of them.

Since I am still new at this I would not recommend taking my new build into Ranked Play unless you yourself are a very skilled Katarina player and think that this build will counter what the enemy team thinks will counter you.

I will continue playing with this On Hit style to see how it measures up to other champions but for example: This build was able to hold its own against a Late Game geared Garen player in a head to head fight, where as normally Katarina would simply have to run away. Granted I still had to run away but the result was that I had damaged him sufficiently that I was able to kite him around while spamming my skills that I finished him off as he ult'd me dead as well.

In ranked games most everyone agrees that when the enemy team picks Katarina before you have picked your mid champion that you should pick Talon, Kassadin, Fizz, Heimerdinger, or Zed. Meanwhile Katarina herself can quite easily counter champions like Lux, Brand, Zyra, Ziggs, or another champion who relies on AoE or skill shots that Katarina can simply dodge with her low cooldown E.

+ To be updated with Enemy Champions and Difficulty Ratings with both Burst and New builds.

I have loved Katarina ever since I first started playing her due to her almost unique amount of mobility. Unlike other jumping champions Katarina is limited only by cooldown, and the need to have a target, but unlike Talon it can be ANY target and also unlike most others her abilities are limited only by their cooldowns as Katarina uses no resource.

Katarina's normal AP Assassin build is still valid and 4/5 I would still use it over this against champions that Katarina counters normally, however against the tougher champions I would fall back to this one as it gives you that needed advantage plus the element of WTF?

Anyway please leave any comments and ratings, any thoughts on how to better improve this build or this guide itself, and any death threats/insults to my intelligence in the section below and once I improve my skill I might write some more guides on other champions.