Talk:Katarina/@comment-1712427-20131226174828/@comment-5920585-20131229135050

Think of the defensive bonuses and utility that are afforded to AP Katarina - namely the armor and stasis from Zhonya's, the MR/MR reduction from Abyssal Scepter, the health and soft-CC from Rylai's, and the sustain from Gunblade (which I don't normally build, but with which I have no qualm). All of the aforementioned items make Kat far more survivable in fights as well as providing AP which makes her damage phenomenal.

My point is, Kat's standard AP items are double-duty - not only do they provide a ton of damage, but they also provide indispensable utility and damage mitigation which many conventional AD items don't provide.

As mentioned by the fellow above me, building AD also forsakes a potential AP scaling of 1.0 from Bouncing Blade and Shunpo, which provide significant damage with an AP build. Think of Kat's passive: if you've built AD, and you activate Voracity after using Death Lotus in a fight and netting a kill/assist, you have to follow it up with your basic abilities which will have obviously come off cooldown. With an AD build, your basic abilities will deal measly damage considering only Sinister Steel scales with AD, as opposed to the combined scaling of 1.25 if AP were to have been built. Building AD makes Kat even more overwhelmingly ult reliant, and if your ultimate is on cooldown, you simply lack the significant damage your basic abilities are able to deal had you built AP.

When I first started playing LoL, a conventional Kat build was Sorcerer's Shoes, 4 Bloodthirsters and a Void Staff, but such a build would be simply inviable now because it almost nullifies the damage of two of Kat's core abilities because they don't scale with AD.