What was the writ that only grand duke and grand duchess people can only come?

Question

i became a grand duchess recently [ just now ] and I wasn't reading properly, but what was the writ that only grand duchess and grand duke can enter at the battle chateau?
and what people will I be challenging there?

Answer 1

The Black Writ of Challenge is the writ that only Grand Duke/Grand Duchess can use. It increases the opposing Pokemon's levels by 20 and also increases prize money.

Source