AP vs Hybrid vs AD

Although AD is viable for the larger bonus damage ratio on your Bouncing Blade and ulti, Shunpo in my opinion is a much worthier ability to improve. Also, think of this: With a full build for Kat, AP vs AD, you can get around double the amount of AP than AD for a similar gold cost.

Here's the math to that. I took my build, total gold cost around 17000 (everything minus the pots), which, NOT including masteries, adds 605 bonus AP. With my mastery setup, you will get around 645 bonus AP, and with flat AP quints, around 665 AP. If you include the random blue elixirs, you will be hitting over 700 AP.

Then I took a full on AD build for Kat, courtesy of HeAt (Katarina - Attack Damage Style). Since stacking items are not very reliable, I replaced his Sword of the Occult with a more stable item, another Bloodthirster. Not including pots, the total gold cost is around 17200. Without the masteries, around 400 bonus AD is gained with full Bloodthirster bonus AD (max 40 per Bloodthirster). This is, keeping in mind, you can keep ALL of those stacks up.

That's almost double the amount of AP than AD for slightly less gold, and the AP:AD bonus damage ratio for both Bouncing Blade and her ulti is 1:2 (double the amount of bonus damage from total AD than from total AP) (exception for Bouncing Blades, AD adds slightly more than double AP: 0.35:0.8) (+0.35 of total AP and +0.8 of total AD for Bouncing Blade and +0.25 of total AP and +0.5 of total AD for Death Lotus). This means that in the same amount of time, since one unit of AP is cheaper than one unit of AD, you will get around the same bonus damage add-on with both your Bouncing Blade and ulti. So, although people think AD will make your Bouncing Blade and ulti more powerful than AP, in essence, you are gaining the same amount of bonus damage, only difference being your standard attack and only a little less damage on your Bouncing Blades. Think about it: with 800 AP it would deal +280 damage, with 400 AD +320. That means you are ditching Shunpo's nuking ability for around 40 more damage on the INITIAL hit of the Bouncing Blade, which has a higher cooldown than Shunpo and less range. Cmon.

Which leaves Shunpo . If you are building Kat AD, you are not adding any damage to your Shunpo. And, as explained above, you get around the same bonus damage on your Q and ulti in the same time frame with both AD and AP. So, why leave Shunpo all alone? Below you will find a whole section on Shunpo, one of my favorite abilites in League of Legends.

And in case you are curious as to why I am not talking about Kat's W, Killer Instincts, in this section, it is because AP and AD both have no effect on it. It only adds a base benefit, which will be described later.