What symbolism? Bones are inside of you. They're what remains of the dead. Death is a natural occurrence. Everything dies. Literally everything will pass in given time. No exceptions. Rituals are in all forms and shapes. Every religion, race and group has their own. So unless you see some flipped pentakles, bloody goats, contracts, goblets filled with blood and succubi anywhere in the game, you have no idea what you're talking about.