(Also known as “After the Divine Realm Collapsed, Did Everyone Become a Pawn?” Dark fantasy + immortal bonds + characters with brains? Villains, not mindless, not a power fantasy, slow-paced? Lots of original worldbuilding. The blurb doesn't do it justice, so read the story!)
“When the kingdom kindles the divine throne with our bones,
I devour the false gods with the Erosion Core.
Beneath the golden jade tree behind me,
a girl's tattoo sprouts the roots of world destruction…”