To clear Chapter 12, you will need to engineer seven distortions. However, their exact locations can be difficult to find. You will need to build up karma by attacking villagers and performing Witch Domination on various buildings, all without the Marginal Gaze facet equipped (since it prevents you from gaining karma). As you gain karma, you can return to familiar maps and trigger cutscenes, which sometimes include battles and which always end with a fight with a monster known as The Editor (its exact form and attacks vary). The final event on the list requires that you have first completed the six prior events before it will appear.
The location of each event is as follows:
Brokenturm - From the Select Pillar, start up the stairs just to the left.
Castle Gate - Head north through this area and if you have sufficient karma and have met the requirements, the final scene follows.
Downtown Amataya - Approach the alleyway on the right side of the map multiple times to trigger a series of scenes leading up to a boss fight.
Near St. Dulche - Visit the house near the far northwest corner of the map, which was previously blocked by a level 38 anti-magic boulder.
Tettara Desert - Visit Lucchini's home village, Hidden Astaro, near the northeast corner of the map. You will trigger an event near the well.
Wudes Forest - Visit the Witch's Garden area, most easily accessible from the far northwest pillar.
Yaptolacca Ravine - Visit the hut where you found the medicine man previously. The scene is triggered just east from there. You may need to raid the hut first.
