Book of Ages

The Book of Ages is the most powerful magical item in the universe that even Demons fear.

Appearance
It is a gigantic book that has millions of pages.

Powers, Skills & Abilities
The book's main function seems to be that it records history, though the enchantments allow anyone who rewrites it to change history to their whim.

There seems to be no limit to what changes can be made, as Jade was able to write that the J-Team inexplicably gained superpowers and it happened.

Uncle even gained the items and power needed to banish several demons simultaneously when Jade wrote that he did so.

The main defense against the book's power is to obtain a piece of the book that details one's own history.

History still changes around them, but they remember the unaltered version of the past, and can reverse the revision by returning the part of the book they removed.

Owners
No One.