AD vs AP Hybrid Kai'sa

IMO, it has to do with how close to the enemy you can afford to be. If you got peel, go for the AD build. If you don't feel confident enough to get real close to the enemy, then you go with more AP-centric build (which allows for purchases that will enhance your )

But that's just a personal opinion, I see that the top players rarely deviate from the +Crit build, so you might wanna follow them :)

I generally go for hybrid, starting AD, then getting AP later to scale harder.

first buy, upgrade it to then grab another ASAP to evolve my Q. Then I buy , finish my , then build . Boom, all three abilities upgraded with buckets of damage. After that, I usually get whatever defensive AP item suits the enemy team, usually .

The strength of this build lies in how quickly the Q gets upgraded. Seriously, it's super-fast, giving you more potent trades and waveclear than the crit build would at that stage of the game, so you can get a lead and snowball easier.