is that an original concept of yours ?
would you like to say something about the backstory?
OK, wild guess: are these priests on a wake sending the caskets of those that passed on their final journey ?
Yes, my idea). I kept the idea in my head that these priests were the keepers of souls. These priests do not allow souls to leave the coffins so that in the future they do not become evil spirits. Dead former criminals lie in the coffins. It turns out that they will continue to be kept in prison after death.