>But Oviposition, threadbare as it is, had given me this setting with the ruins of an ancient subterranean civilisation, dead gods, and a bunch of hapless archaeologists.

The angst my characters needed required me to work into that setting a complex and subtle magic system that embedded political complexities in the world and in the characters very bodies and personalities. What I needed for the characters shaped the world I created, but that world needed to be full and rich to support> 

 >characters with the kind of complex issues I wanted them to have.

And all so they could bone and feel angsty about it 😅