I am not capable of seeing my own illusions, Vash. Nor was I in the right state of mind to design an illusion in a particular way.

I don't know what you saw, but I suppose it is possible the sun setting was simply meant to reflect the amount of time it takes for an entire soul to be consumed when done at a steady rate. Had your soul been entirely consumed, you would have either been released from the illusion or died. Though without a soul, I can't imagine you'd live very long. Most creatures who survive the process will attempt to end their own life due to the intense pain of being entirely separated from their soul.

[...not the kind of thing Cheyenne usually talks about, but she's still not exactly in her right mind. Not insane anymore, no, but very disconnected from her usual limited emotions.]