Codex of the Finite Planes

The Codex Keepers have devoted their lives to understanding the mysteries of the multiverse by studying the legendary Codex of the Infinite Planes. However, this powerful artifact is notoriously difficult to track down and dangerous to possess, so the Codex Keepers have created lesser versions in the halls of the Citadel of Arx Infinitus. Each of these items are still powerful, but a codex of the finite planes involves less risk in its use.

Each codex of the finite planes appears as a large book, roughly two feet tall and half that wide, with thin metallic sheets of paper between black ironbound covers. They are surprisingly light, however, each only weighing 10 pounds. A silver clasp keeps the book closed and can only be opened by the attuned holder. Inside, the book holds a theoretical infinite number of pages, many filled with scrawled handwriting from hundreds of users in a staggering variety of languages.

The knowledge contained within the codex of the finite planes can help understand the nature of the planes. Up to three times per day, you can cast a special version of the legend lore spell while holding the codex to tap into the vast pool of knowledge inside. The subject of the spell must relate somehow to one of the planes of existence that is not the Material Plane (ultimately up to the Dungeon Master to determine).

Each copy of the codex of the finite planes is linked to the other copies, so when an attuned wielder writes down information in it using a special quill and ink created in the Citadel of Arx Infinitus, the information magically appears in all other versions of the item. Several sections of each copy are devoted to messages between the planar sages of the Codex Keepers, offering hints and details on current and former projects.

Each codex of the finite planes has 10 charges. While holding it, you can use an action to expend 1 or more of its charges to cast one of the following spells from it, using your spell save DC: astral projection (5 charges), banishment (3 charges), etherealness (3 charges), and plane shift (4 charges).

The codex regains 1d6 charges once every 24 hours. If you expend the last charge, roll a d20. On a 1, the codex blackens and the pages crumbles to powder.