How does Kurtrus hero power in solo adventures work?

Singleplayer Discussion
1

Just read hearthstone dot fandom dot com slash wiki slash Kurtrus_(Book_of_Mercenaries_3)

but I cannot get rank 3 doesn’t matter if I attack or not no rank 3 option after rank 2 its only fashion weapon option how do I get fashion weapon rank 3?

2

What boss are you currently on? The hero power progressively becomes stronger the further you advance in the adventure.

-Valas

3

First boss or possibly second boss I kinda forget as I finished the adventure.