German:
Wenn man viele Kills bekommt kann man statt "Abyssal Scepter" kann man "Mejai's Soulstealer kaufen.
Die Zauberschuhe: Madiedurchdringung.
Hextech Gunblade und Wille der Uralten: Zaubervampier.
Rylai's Kristall Zepter und Abyssal Scepter: Leben und Magieresistenz
(Abyssal Scepter kann man auch weglassen).
Rabadon's Todeshaube: Fehigkeitenstärke.

English:
If u get feeded by the enemies u can use Mejai's Soulstealer instead of Abyssal Scepter to increase ur ability power, of u buy Archangel Staff instead of it.
I buy these items because of: ...

Sorcerer's Shoes: Magical penetration

Hextech Gunblade and Will of the Ancients: Lifesteal (dont now the right word in english, but i think u know what i mean ;) )

Riylais's Cristal Scpeter and Abyssal Scepter (U can switch Abyssal Scepter, see above): Health and Magical Resistance

Rabadon's Deathcap: Ability Power

This was my Version of Katarina.

Comment and rate so i can improve it

Have fun

-Downhilas-