Story-related, cannot miss.

After unlocking The Storm Calmed (100G) achievement at the end of chapter 5, part of the beginning of chapter 6 will see you head into the forest of confusion on your way to reaching Borgavirki (Thorgestr’s home).

Once you’ve made it through the trippy woods and got out the otherside, once you get to the steps of Borgavirki, you’ll gain control of Senua again and this achievement will unlock, midway through chapter 6.