Katarina is rouge there can use Ap and Ad. 1st you need to be carefull with playing Katarina. Items you need.1st. Boost of speed. 2.3x Health potion. 3. Mejai's soulstealer. 4. Rylai's crystal scepter. 5. Zhonya's ring. 6. Void staff. 7. Mercury's treads. 8. Nashor's tooth.