This twisted little morality play is what enticed me to join MC Comics in the first place. I continue to love it and am glad to see another installment.
We've known that Tari put it there since the beginning, we just didn't know why. I presume it was to escape from Clovis's influence (dunno how that's working out for her).
I don't know but I love to have a theory. I think the book is of Infernal origins. I think it has a mind of its own, and that mind is to maximize the spread of corruption. Tari has been enslaved by the book's owner(s?) for quite a while. She seems to have a strange sort of 'independence' when it comes to changing the book's location (something Clovis would likely have forbidden provided he could think of all the ways his orders might be interpreted). She also seems to manifest in visions to drive the book's owner towards greater acts of depravity.
It is possible she is more a slave to the book than to any particular owner. I would suggest that Clovis died because the book saw more potential for evil in corrupting Daffyd than continuing to serve Clovis. Clovis may have been corrupt to begin with, which meant less opportunity for a harvest of souls. Also, Daffyd is more resourceful and imaginative than Clovis, which means he may in time ultimately do more damage. While it is true the voices tried to drive him down the dark path too quickly and he put the brakes on, removing some of the more destructive influences he had placed on the women in his circle, he did not divest himself of the book and its powers, or seek to destroy it, so this may be just a minor setback for a patient villain such as I imagine this book to me.
Only the author would know how much of my speculation is correct, of course.