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.
This is my first build.First buy Rejuvenation Bead. Katarina is a good harasser with Bouncing Blade. Harass a lot with Bouncing Blade.Then buy Spirit Visage. Then buy Berserker's Greaves. Then start buying Bloodthirsters. Buy as much Bloodthirsters as you can. You will be doing a lot damage. Try killing as much minions as you can for your Bloodthirsters. Hope this build helps you guys!