I figured it out.

[snarp]

I had previously expressed concern about how people who are already dead can die. It's because people in Bleach die and go to Yami no Matsuei, and people in Yami no Matsuei die and go to Bleach.

Comments

[octopedingenue]

There's some point at which this exchange of energy breaks down and causes the heat-death of the universe, but I haven't figured it out yet.