First dive into the Nest 

You need to be interknot lvl 45 to unlock it

@@painpeko4415 thanks, Im still 40. You are fast reaching 45 already

@@pimlapassmitthapipat4158 nah man, i just got to 40 this day, just i Saw a lot of people already 45+ when they fight nineveh(the boss on the video)