1. The Book: This is the most obvious symbol, representing the central object around which the series revolves. It could be depicted as a closed book, a book with a spine that's glowing, or even a book with a keyhole on its cover.
2. The Serpent: This symbol represents the world of Lies, its power, and its connection to the human world. It could be a stylized serpent, a serpent with a key in its mouth, or even a serpent entwined around the Book.
3. The Key: The key is the object that unlocks the world of Lies and allows people to access its power. It could be a keyhole, a key itself, or even a keyhole in the shape of a serpent.
4. The Tree of Life: This symbol represents the connection between the human world and the world of Lies, and the potential for both good and evil that exists within this connection. It could be a stylized tree with roots that reach into the earth and branches that reach into the sky.
5. The Hourglass: This symbol represents the ticking clock, the countdown to the final battle, and the limited time that the characters have to make their choices. It could be an hourglass, a clock, or even a stylized image of sand flowing through time.
Important Note: These are just suggestions. You can be as creative as you want in your interpretation and find symbols that resonate with you. Consider the themes, characters, and plot of the series when deciding on the symbols you want to use.