Here's some of what David Mervik, the Senior Narrative Designer of Little Nightmares, had to say in an interview: Using what breadcrumbs the devs have given us and in-game evidence (which most fans fans either miss, ignore or undermine), here's my explanation of why Six dropped Mono (which I have copy and pasted from a comment I made several months ago on YouTube): Credit goes to PurpleMNinja for this literally perfect explanation. This was copy-pasted from the Little Nightmares fandom.