For the dark species, especially the powerful dark species, as long as there is a glimmer of hope, they will not sacrifice their souls.
Because as long as they still have a trace of soul power, they may be resurrected.
As a demon-level existence, that bone is not easy to kill. As long as there is a trace of soul power to escape, or leave a trace of soul in the dark world in advance, it is impossible to die easily.