>>11358155
What about soulbinding as a way to bind ghosts? As in, slave contracts with a soulbinding clause last after death, and so many slaves end up trapped as ghosts in the afterlife, with hundreds of years left on their sentence?
Naturally, ghosts do not have human rights, and they may be fitted with spectral restraints that are impossible to remove. Ghosts can't even try to escape slavery by killing themselves - their only release will be to fulfill their terms.