Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Very short POST-PATCH (this means multiply the mark values by 3) Katarina build, I don't care about your AP build. I'm an assassin, so I kill squishies, that's all I have to do to win. Allow your team to take care of the rest. If you have any doubts about my build or play style, add me on EU, IGN = JonKo. I hope you enjoy this seemingly generic build, if you commit to it you may find its true versatility to fit your play style, as well.
Pretty straight forward, AD marks are obviously not updated on this site but instead of Mpen marks, get flat AD marks to be able to hit harder on BB, new death lotus, as well as that one auto-attack after shunpo (!).
Mpen is still great, but you'll get enough with boots. Get a haunting guise if you're not solo lane.
Katarina is horrible vs Magic damage & cc, so m.res masteries, glyphs and abyssal scepter if there is room for it will mitigate a lot of damage from any spells. Beyond getting a banshee's or sash, there's not much else you can do.
Speaks for itself, R>Q>W>E, get 1 level in E, obviously.
How to use those skills
Harass with Q only at high levels, at low levels harass with Q and E vs squishies. When going for the kill: Q -> W+E -> R or W+E -> R -> Q when enemy runs. Congrats, you won mid.
Item Build Order
Doran's Shield + HP Pot
First Return: Boots of Speed + B.F. Sword
If Failing: Boots of speed + Elixir of Fortitude OR Sorc Boots (Wards)
If Owning: Sorc Boots + B.F. + Elixir of Fortitude (Wards)
Following returns: B.F. Sword + B.F. Sword + B.F. Sword into BTs (Wards) -> Win.
If Failing due to Magic Damage: Abyssal Scepter + B.F. Sword + Elixir of Fortitude (Wards)
If Failing due to Attack Damage: 2x Sunfire Capes + 2x B.F. Sword (Wards)
If Failing due to cc: Banshee's Veil & lots of luck/skill.
Doran's Shield + HP Pot OR HP Crystal
First Return: Sorceror's Boots OR Haunting Guise + Boots of Speed
Following Returns: Rinse and repeat solo lane.
Final Item Build:
The Bloodthirster x 4
The Bloodthirster x 2 (3)
Sunfire Cape x 2 (3)
I'm probably the only Katarina player that takes Ignite and Teleport. I expect QQing about not being able to hit DeathLotus without a slow from Rylai's or Exhaust. Well, I play mid lane 90% of the time, and teleport allows me to have extreme mobility at early levels even without proper boots. I can rush B.F and kill squishies giving the team an early advantage.
Since the latest patch, Death Lotus hits 3 enemies from level one, meaning that ganking has become even easier now, lucky you. Death lotus has a very low cooldown, so I don't care if I don't get a kill with it, with all that damage they either have to blue pill or they stay and get killed by BB/Shunpo/Ignite. Try to use DL as a replacement for vision wards or oracle's, since it lights up whenever stealth chars are near. You might not kill them, but they'll sure as hell be freaked out enough by your superior detection abilities to make a mistake or two in the process.
Combined with wards, teleport and shunpo are extremely effective mobility and mind-game tools, which is why I use them. Feel free to use flash/exhaust/whatever you want, but this is my build, which I'm sharing with you. You're welcome.
Obviously, when you're not expecting to play in mid lane, you might want to take some other spells.
A final note on item builds.
I don't like reading guides on how to play or how to build a character, so I hope you don't take my word for this build. The point is to deal as much damage as possible, and if there's a problem, hard counter it. Wait, let me repeat that, hard counter it.
This means that if an enemy auto attack AD carry, let's call her Ashe, is feasting on the Teemo in your team, you do not blindly get more BTs. A Thornmail, for example, would completely nullify her effectiveness vs. you and, while you might get flamed by your team mates for it, this could give you the edge you need to win the game.
"But JonKo, Katarina is not a tank, I just wanna kill people! T_T". No, **** that ****. You want to win? Then learn to sacrifice cheesy sound effects from an 80-year old woman for actual team play, counters, map control, and general proness. This game is supposed to become as competitive as something like StarCraft2, so stop noobing around and be useful to your team.
Hope you enjoyed this little build. See you ingame.