Divinity: Original Sin - Enhanced Edition

This is unmissable and you'll arrive here as part of the main story, but its a little tricky to figure out exactly what you need to do to complete the area. Spoilers to follow, obviously.

Once you Find the Wizard, teleport back to the Homestead and Zixzax will open a final portal (to the left of where you spawn in). There is a chest with some of the last loot you'll come across behind the portal if you go around to the right.

The first part after the clearly stated PONR is linear, though if you fail to answer the giant threatening Leandra the way she thinks you should be answering you are teleported back to the beginning. Tell her what she wants to her, admit you're worms and deserters and you'll get through this section.

The achievement pops here, but I've included some guidance on how to get through this area with minimal frustration.

Next you'll arrive at an alternate dimension King Crab Inn with everything spelled backwards, the Trife (Efirt Eht) tending bar and many key players from your travels chatting amongst themselves. Go to the cellar and find a key in a book in what was a trapped room in the original King Crab Inn. Don't bother looting anything else, as it'll just explode.

Go upstairs and the key will unlock one of the doors to a room on the first floor. Inside you'll be threatened by Leandra again and, in an homage to the Chronicles of Narnia, can transport yourself to the second floor through the wardrobe. The first room will feature a crab with a crown. Enter the wardrobe twice more until you're in a room where the door to the main area of the second floor is blocked by a blue stasis field. Play with the paintings on the wall to your left from the wardrobe to unlock the stasis and exit the room.

Follow the path out of the inn until you can turn right into a room that looks like it is falling apart. Exit onto some rocks at the back of the room and head towards the far end of the clearing.

You'll find a pyre with Astarte (Etratsa) and several mourners at the end. Cast a fire spell on Astarte to cremate her and loot her ashes for a key to the next area. I was bombarded by fire damage when I went to loot the key, so beware.

Head back to the main path and turn right. You'll reach a locked door at the end and you'll have completed the Nni Barc Gnik.