The Codex could integrate the game's collectible items (Memories) into the spirit entries. For example:
Taking inspiration from the game's meta-horror elements, the Codex could occasionally be "corrupted" by . Tutorial text within the guide might shift into sinister, misleading instructions that try to trick the player into a Game Over, forcing you to discern between Haru’s actual notes and the spirit's deception. yomawari-midnight-shadows-codex
Hints on whether to use specific items like pebbles for distractions or salt for protection. The Codex could integrate the game's collectible items