I'm pretty sure it's not real. There's no concrete evidence or reliable source to confirm its authenticity. It could just be a story someone came up with for entertainment.
I don't have the exact name of the person who created the Omori manga at hand. It could be worth doing a search on manga databases or asking fellow manga enthusiasts for the answer.
Omori is purely fictional. The story and characters were imagined by the creators, not drawn from real-life events. It offers a fantastical and imaginative experience for players.
At the moment, there's no definite date for the Omori manga release. But you can follow the official social media accounts or manga forums for any potential news or leaks.
In fanfic, when Blake inserts a magazine in Gambol Shroud, it could potentially be a way to show her preparing the weapon for action. It might be part of a combat - related scenario where she needs to ensure the weapon is fully loaded and ready. It could also be a symbolic act, perhaps representing her taking control or making a decisive move in the story.