This is my build for Katarina, the Sinister Blade. The builds I use for Katarina are strictly AP and Magic Pen. Well, enough wasting your time reading this, let's read the more important info.

PS. Leave a comment if you like it (:D) or not (D:).

Pros
- CD's are extremely short.
- Can get away from ganks easily
- Can chase easily
- No mana.
- One of the most dangerous fed champions of the game.

Cons
- Pretty squishy
- Focused first in teamfights
- No CC's

Bouncing Blade - Katarina throws a dagger that bounces from enemy to enemy, dealing magic damage.
Katarina throws a dagger that hits up to 2/3/4/5/6 enemies, dealing 60/95/130/165/200 (0.35 + ) magic damage. Each subsequent hit deals 10% less damage.

Personally, Bouncing Blades isn't one of my favorite moves, it does less damage than an usual move and it's pretty boring... in a way, but it is very helpful.

Killer Instincts - Passive: Katarina's attacks deal increased damage. Active: Katarina's next basic attack has a bonus effect. Bouncing Blade deals full damage to every target hit and reduces incoming healing to the target, or after using Shunpo Katarina takes reduced damage for 3 seconds.
Passive: Katarina's abilities and melee attacks deal 8/12/16/20/24 additional damage each hit.
Active: Katarina's next basic ability has a bonus effect.
Bouncing Blade: Deals full damage to every target it hits and applies 50% healing reduction for 5 seconds.
Shunpo: Katarina takes 15/20/25/30/35% reduced damage from enemy attacks for 3 seconds.

Killer Instincts. Again, really helpful. The general passive from the move benefits my ult a lot.

Shunpo - Katarina instantly moves to her target's location. If the target is an enemy, she deals damage.
Katarina moves to her target's location. If the target is an enemy, she deals 80/120/160/200/240 (+0.75) magic damage to the target

I don't think I could live playing Katarina without Shunpo. Shunpo is one of my favorite moves. It has a extremely long range and it's like an instant flash to enemies AND allies.


Death Lotus - Katarina goes into a state of extreme focus, throwing daggers with unrivaled speed at up to three nearby champions.
Katarina goes into a state of extreme focus, throwing 10 daggers over 3 seconds at the closest 3 enemy champions. Each dagger deals 50/65/80 (0.25 + ) magic damage.

Death Lotus. Just OMG. Scales #3 strongest ult of the game, next to Nunu's #1, and Galio's #2.

Ok. My item squence is pretty simple.

First you open up with the Amplifying Tome and a Health pot.

You build the Tome into a Mejai's if you are doing good... if not build it into a Morella's.

Then you get the Boots of Speed and quickly build it into the Sorcerer's Shoes.

After that, you get the Hextech Revolver. Wait. I don't build it into the Gunblade yet. I wait for the Deathcap and then get the Gunblade.

The reason why I dont build the Gunblade right away is that you spend too much money getting the Bilgewater Cutlass. After you get that, others might have already gotten something even better. Katarina doesnt need the Cutlass. All she needs is the SV and the AP and the equip (I will explain later).

I get the Deathcap so I keep up and later excel in battle. I use the Deathcap as my "carrier" to get me up to the required destination of the Gunblade without buying the Cutlass.

After that, I build my Rylai's for the slow and the HP. Katarina is really squishy so she really needs the extra HP for the team fights.

Zhonya's Hourglass is my last item. As listed in the Cons, Katarina is commonly focused in team fights. After you jump in and use your ult, you freeze. Letting you teammates clean the rest up and letting you get the winning assists and mostly kills.

My Skill Sequence is a bit different.

I grab Shunpo first for the instant flash to enemies and allies, and also the long range.

Then I grab Bouncing Blades. For the Bouncing-ness. It helps with farming and last minute kills.

At lv 3, I grab Killer Instincts.

By now my main skill combo is

Q + W + E (before my ult)

If you are harassing a low hp stubborn idiot. Use Killer Instincts on Q.

From then on, I don't build Killer Instincts. I just go

Shunpo, Bouncing Blades, Shunpo, Bouncing Blades, Shunpo, Bouncing Blades, etc.

Until I hit 14 and run out of ranks to put it in.

I grab my ult at the usual 6, 11, 16.

If you played Katarina, one of her most annoying aspects is that she can't slow, stun, snare, etc. That's why you grab Exhaust.

I grab gunblade not only for the AP and SV, but for the slow too. I've noticed that not a lot of people actually use the equip on the Gunblade. It is actually useful when you are chasing and your blades arent long enough.

Heal.

I grab Heal because of the fact that Katarina is focused a lot and also very squishy.

A tip is that you can use Heal when you are spinning. That helps alot and that extra lets you use Zhonya's and clean up the rest your teammates have set for you.

Ways to use Bouncing Blades to your advantage to get a kill.

- Enemy is T hugging (with low hp)... use Killer Instincts on your blades and shoot it to a nearby minion to get the kill.
- After requiring Rylai's, use Bouncing Blades to slow the enemy and Shunpo and finish him off with your ult.

Shunpo. (my favorite move)

- You are chasing an enemy. You Shunpo to a nearby minion. You do one of three things:

Throw knives when you have Rylai's OR use equip on Gunblade, OR exhaust.

You then run AHEAD of the enemy and drop your ult. If your opponent isn't thinking, he/she will run past you and die or the opponent will run the other way.
Make sure you have an ally behind to you block that.


Death Lotus.

The passive from Killer Instincts benefits Death Lotus a lot. Every single dagger does a certain amount of damage more than the last.
In other words, say your daggers do 100 damage each.
Your damage output would turn out like 108, 112, 116, 120, 124, and the rest of the 5 daggers would do 124.

I love having a champion with a CC type of ult.

My Favorite Teammates are Ammumu, Nunu, and my Favorite... Galio.

Arrange with your teammates to use their ults when they see you use your ult.

In other words, Kat use ult. Galio sees Kat use ult. Galio use his ult. Everyone on enemy team dies. :D

I take Magic Penetration runes, AP runes, and also AP per level runes.

...

That's it.

...

Oh yea, Do not take hp or mana runes. HP isnt necessary. And Mana.. well.. if you can't figure out why not to take mana runes... uninstall the game.

I take the build of

9/21/0

I put the nine points of Offense into Magic slots and also Improved Exhaust to chase.

I put the other 21 points into Defense. Katarina is really squishy ( I know I've said it a lot of times) so I need to get the extra armor.

When your enemy lane turret is down, you start ganking to help out your teammates, right? The best way to do it is to hide in the bushes and signal your teammates to let the enemy push. Once the enemy is near the turret, you Shunpo to a enemy, exhaust them, and run TOWARDS their turret and then drop your ult. They would have to run past you to get to safety. 90% of the time I do this, I get at least two stacks of Mejai's. You block off the jungle lanes so they don't run off into the jungle and get away. If they run into the bushes, quickly run the bush closest to the enemy turret and finish the enemy there.