This review is written following a re-read, as I'm preparing to tackle "Godsdoom-2".
The book is focused on a single battle between the Young Gods and Old Hroft and rest of the Ancients- which means it's a heavily co-opted Norse myths saga, but that's besides the point. The point of the book is the background info, and specifically the annotations and musings of Hedin, who is reading the manuscripts, which is something like Hroft's Memoir. These annotations help to fill in the blanks concerning just how the Young Gods gained so much power in the Consistent.
The book's plotting is good, although the pacing may feel a bit uneven due to sometimes overly-ornate language used to keep up the style of the sagas.
That being said, it's an entertaining read that helps to fill in some blanks concerning an event that's been frequently mentioned in the series prior to this.