Book of the Dead

Season 1
Xylo got it around the end of season 1 after making a deal with Thanatos.

Season 2
Xylo discovered that there are multiple books of the dead including an Egyptian Book of the Dead and a Norse version called the Book of Shadows. Inpu and Magnus are in possession of the Egyptian Book of the Dead, while the Book of Shadows entered and possessed Magnus Thus managed to get Xylo book of the dead by almost killing him, ripped inpu arm off to get his and killed the whole world but was stopped by xylo and inpu