Her skills scales with Ability Power as well as Attack Damage. I tried to do a hybrid build to see it's power. On this video I could be able to Solo Baron with AP KAI'SA build on lvl 15. His Q skill damage is insane. I wonder if anybody tried this on a normal or ranked game? Please give me feedback if you find it OP! 
3400g 
3000g 
3500g 
3100g 
2600g 
2625g =18225g
Do you see the problem yet?
it does
but if you go ap you go ap you dond't build ad items
[zombie-brand-mindblown]
AP Kai'Sa is even intended to work
You should try this again either with 45 minutes on the clock instead of 20 or 2 completed items instead of 6. The result will be way different.
The best build in my experience is rageblade, gunblade, ad item (preferably bork), full ap. You get significant attack speed, access to your upgraded q for waveclear, and then all of the ap (the stat she scales best with imo). You'll get 25%+ execute damage on passive, plenty of attack speed to function as a consistent damage carry, w and q hit like a truck, and you have a lot of the utility ap items to choose from like 
etc.
Kaisa's ap ratios are actualy trash compared to ad. Her w the thing that gets an ap upgrade has an ok ap ratio for a ap poke mage but when u bulid ad raw ad it does so much mor damage. even her ult had an increasing ad ratio as u put points into it but the ap ratio is so bad.
Yea it is, but that build did not do it any favors [sg-ahri-3] 
Now that's a real ap Kai'sa build. Land one q and watch half their health go boom. Get the cd reset through another. STILL NOT DEAD? Ult, Gunblade, Q. [slayer-pantheon-rainbows]
A legitimately garbage looking build.
Why death’s dance? Why not guinsoo’s rageblade?
Why rylai’s?
Why liandries?
The only good parts of that build are the gunblade and nashor’s tooth!
Lich bane Deathcap gunblade nashors guinsoo’s is pretty much the build you have to go.
Perhaps you can substitute the lich bane, probably with, say, a triforce to top off the AD in exchange for movespeed, attack speed, and mobility, but overall that’s the build to go if you want to be AP, and it’s an expensive as hell build.
ur full build at 21 mins because you gave urself free gold. that will NEVER happen in a real game.
