For runes, I take Magic Pen reds, Scaling HP yellows, AP blues, and Magic Pen quints. Sometimes I also take ~3 AD reds, just for a stronger early. The Magic Pen is incredibly important, as it nullify's a large portion of what your opponent will be buying against you. The scaling HP is standard, and allows for more survivability later game. AP blues are for a stronger later game, as they scale with your ult much harder than AD does.

For masteries, I take Thunderlords, which is standard on Katarina. The only noticeable difference in my masteries as opposed to other Kata builds is that I take points in Intelligence for the CDR as opposed to the MPen that Precision gives. I just feel that post Shunpo nerf, the extra CDR is needed in order to have a more potent early game. The MPen we're giving up for this is very little in comparison to what we will be buying/runes.

Starting items are always either Dark Seal or Long Sword, depending on lane opponent. Dark Seal against opponents with more poke and Long Sword against opponents that we can secure easy kills on early. Boots first item is NEVER viable.

Once we get to boots, I most often upgrade them into Sorcerer's for the MPen. Sometimes I'll also take Tabi/Mercurcial, depending on how oppressive their ADC/Assassin is.

Hextech Gunblade (HGB) is our staple item, for every game. It provides great stats in AP and AD, gives us sustainability, and allows us to burst down targets without worrying about them running away. Second item I normally take a defensive one, be it Zhonya's, Hexdrinker, or Spectre's Cowl. Hexdrinker builds into Maw, which is another good item on Kata. Spectre's goes into Spirit Visage, and who's complaining about more HP, Healing, and CDR. After that I'll normally start buying offensive, taking items like Void Staff, Rylai's, and Rabadon's. After that, let your imagination run free. It literally doesn't matter, as long as you're getting AP/Tank items.

Always start Q, it allows for early poke and is great for farming. Take E second, which allows for stronger poke and better farm. Third take W. Now you have a simple combo, which goes like this: E onto opponent -> Drop W dagger -> Throw Q dagger -> Pick up W dagger -> E onto opponent near Q dagger. Always remember that Shunpo deals damage as well, so remember to Shunpo to them - not the daggers - if possible. From there, most common maxing order is
Q > E > W, and ult whenever you can. Feel free to take early points in E if you don't have much CDR.

Remember the passive - Whenever and enemy champ that has been damaged by you in the past 3 seconds dies - All of your abilities receive -15 second cooldown. Thats all of your basic abilities, and a large part of your Ult. Multiple kills can reset your ult altogether, and allow for massive burst damage over a short period of time.

Flash doesn't need explaining, but for the sake of the guide: Use it to get out of sticky situations, to catch up to targets (If Shunpo is up this can cover massive distance in a short amount of time), and to engage in team fights if Shunpo -> W will be too slow.

Pros
- Strong early game
- Good poke
- Amazing wave clear
- Great Burst
- Fun

Cons
- Falls of late game, try and end early
- Cooldown reliant
- Rekt by most CC
- Squishy

The most common error I see when playing Katarina, is when your team doesn't engage and draw out CC in team fights. Try and motivate your team, get them confident, and work together to take objectives. If you do all of this, they should hopefully have some sort of confidence. Once this baseline is down, you can teamfight properly, even without mechanical skill. You can play team fights 3-4 ways as Kata.

1 - Sit in bushes along exit routes from the fight, with a control ward down to make sure you aren't seen.

2 - Be the first to engage after tanks to deal massive AoE damamge. You will most likely die, but it will give your team a far greater chance at cleaning up successfully.

3 - Assassinate back line. Simple as that. Wait for the cooldowns to be draw out, then hit them with the force of a Semi-Trailer right in their ***.

4 - Wait for cleanup and get a Penta. Easy Katarina logic.