O Último Elo Mortal

The intricate power struggles add depth, but I'm curious whether this was inspired by real-world history or entirely imagined. Was it planned from the start?

I loved the depth but found some parts a bit slow. Do others think this was necessary to build the world or could it have been trimmed?

The magic feels so layered and integral to the plot. I'm wondering if it was based on any particular myth or entirely a creation of the author's imagination.