Get witch secret

[Turk]

How I do to take this secret?

[Khorne Flakes]

Adopt a learning lifestyle and an event may occur offering you the chance to become a witch. Otherwise someone close to you who is a witch may offer to make you one... And of course the Ruler Designer, but that only works for a new game.

It's best to become a witch early on while your dynasty is small. If you can convert most people of your dynasty into witches, you can found a coven and get some really good bonuses for the rest of the game.

[sbudy]

What Khorne Flakes said, but you'd need high learning (>13) in order to get the witch secret event and pass the relevant roll successfully.

Edit: A good way to bypass low learning issue is to change your spouse task from "assist ruler" (default, multiple skills bonus) to "patronage" (learning bonus) before the event, or even entirely if your learning is really low and the spouse bonus is significant.

That's how I got it with Mr. Halfdan Whiteshirt.