Oh, i men't to put E sorry haha.

Not to troll but this is a TERRIBLE guide. First of all you max out the Strength of Spirit mastery which gives health regen based on maximum mana. Too bad Kat has a grand total of ZERO mana. Secondly you will be doing no damage with this setup. Magic resist will still stop you and unless you have a superb early game then you will never farm all of those items. Kat is best played around maximizing the damage of her ult. If you know when to shunpo in and your team is competant, you don't need more than 1 survivability item.

Shows you much you know, i spec nibbleness not regen HP.

its not hard cus u are mid laning if u get last hit on creeps for a while u have gold and when u are lvl 6 u are lvl enough to kill him in mid easy cus hes on low life and when hes dead u finish of the creeps and walk to the lane with lowest life champs and throw ur knife shumpo and ulti simple as that .(im only lvl 19) so i dont know how good ppl are at higher but works perfekt for me

....

Um look at your mastery screenshot again please.