Well, without more details, it's hard to say exactly what the 'Sunk into the Womb' true story is. It could potentially be a story related to a very deep emotional or psychological experience. Maybe it has to do with a person's journey back to their roots or some sort of rebirth - like in a metaphorical sense of going back to the 'womb' of one's origin. But again, this is all speculation without more information.
One idea could be exploring the origin of the cults in the game. Maybe a fanfic could focus on a character who discovers the ancient secrets that led to the formation of these cults, and their journey to either embrace or fight against it.
First, give the character a clear motivation. For example, if they are in a cult, are they there for power, knowledge, or something else? This will drive their actions throughout the story.
Poor character development can really ruin a novel. If the characters are one-dimensional or their actions don't make sense, it can turn readers off. Also, inconsistent writing style or grammar mistakes can detract from the reading experience.
The story might focus on the hero's growth and transformation as they encounter various obstacles and friendships in the world of a thousand drunken monkeys and Thera. It could involve elements of magic, courage, and self-discovery.
One similar book could be 'Awakened: Online'. It also has a great Litrpg system and engaging characters. Another one is 'The Land: Founding, which shares the theme of a character building their power in a virtual - like world. And 'Dungeon Born' is also a good choice with its own unique take on the Litrpg genre.