This is my first build. I use Katarina a lot and her weaknesses are lots of crowd control. Katarina can either build pure AP or hybrid. My build for her is hybrid with lots of AP, some Attack Power, and a little tank. Kat is fun to use even if she's not fed. As soon as you get your Hextech Gunblade, you should start doing better if you use combos. Well hope you enjoy my build!

For the items, it can vary depending on the team you are against. If you're not doing well you can skip the Mejai's Soulstealer for another Rabadon's Deathcap, Zhonya's Hourglass, or a Quicksilver Sash which is like a free Cleanse. You're builds can vary if you are playing against many tanks and get a Void Staff instead of any other item so you can increase your damage output. Katarina has a great damage ratio so the abilities can deal over 500 damage if you build it right.

For the spells, Flash is a great spell because of mainly Blitzcrank. It helps you get away really easily just like Shunpo. So between Flash and Shunpo, it should be easy to get away. Cleanse is a great spell because it gets rid of all the annoying crowd control effects. You can also get Teleport because it gets you to minions, wards, and mushrooms quickly and can easily help you defend of destroy towers. Now the worst spell for Katarina is obviously Clarity. Katarina has no use for mana so Clarity is a huge waste.

Skill sequence is not very important. You should get your Preparation about once before you get your ult. Try to max out Shunpo first and then try to get Bouncing Blades quickly. Katarina's Ultimate Death Lotus is great because when it is maxed, you can do +800 damage if all ten blades hit. It does great amounts of damage. When you go in a fight, go in after most of your team has gone in just so they won't focus you much. When you are pretty sure that you'll be safe, activate Killer Instincts, Shunpo, Hextech Gunblade someone, Bouncing Blades, and then Death Lotus and then if you have Rylai's Scepter you are practically ensured a kill or assist as long as you're not alone. So basically in summary, Katarina's abilities are really overpowered and she is great and overpowered.

For Katarina, I start with an Amplifying Tome and 1 Health Potion. The 1st ability I get is Shunpo because Shunpo brings you to the enemy champion, does a good amount of damage, and lets you get at least one attack on the enemy. So basically, Shunpo lets you do over 100 damage in about 2 seconds. OH WAIT!!! HERE'S A WARNING. Be careful going into the bush alone if you're top or bot. The enemy champions can easily harrass you one on two. Well now that's done, Katarina can really spam lots of damage with her Bouncing Blades after using Preparation. Try to stay in your lane until you get to level 6 with your Ultimate, or when you have enough money for a Hextech Revolver. Then I try to lane and get kills with Shunpo and Bouncing Blade. Then after a few kills and assists plus some farming, you should be ready to buy the most essential item for Katarina (You know what, I'm going to start calling her Kat) in this build. THE HEXTECH GUNBLADE... The Hextech Gunblade has a great lifesteal and spell vamp bonus so it helps you heal a lot. As a bonus, it's active also slows the opponent by a lot. So you just Shunpo in, Bouncing Blade, Hextech Gunblade's active them and then Death Lotus, they probably wont escape. So basically I gave you a preview of Early Game.

Well, if you have been following my build, by level 11 you should at least have Hextech Gunblade, Sorcerer's Shoes, and a Giant's Belt. If you have been doing well, kill stealing with Death Lotus, (and yes Death Lotus steals many kills) then you should at least have a Rylai's Crystal Scepter. After that you should start to build a Mejai's Soulstealer. I know it may be dumb to get a Mejai's Soulstealer this late in the game, but there are more important items for Kat, but it is still very easy to max Mejai's Soulstealer. You really have to wait for other people to go in 1st because Kat get's focused a lot, and she's really squishy. Then you go buy a Rabadon's Deathcap or if you don't have enough money yet, go buy a Needlessly Large Rod. After that you should finish with a Guardian Angel which use to be a lot better, healing 40% of your health but I guess it doesn't really matter with Kat because she doesn't build a lot of health. So basically it would be hard for you to die after you finish your build unless they all aim you. Well that's a Kat's game for you.

So, I hope you enjoyed my build. Katarina's has a great AP ratio and she can easily get kills and assists. So I hoped you can buy Katarina, The Sinister Blade. I hope you do well in all your games. Please comment on how I can make it better. I hope you enjoyed my build and Good Luck and Have Fun!