Finally, the long awaited final episode! Although episode 11 answered a lot of questions, there were still some lingering ones yet to be addressed, as well as what exactly is to become of Mister Pig. As there was a month long delay until this final episode's release, Aniplex released a finale PV just a few days prior to recap the past episodes (link to my translation upload).
This post contains my thoughts as a novel reader, but since episode 12 wraps up volume 1 of the story, there's no real spoiler warnings to be had as it'll just be me filling in the details that were left out by the anime adaptation. Lastly, you'll find any news regarding the series which came out over the past month in the update section at the end.