Board Thread:Questions and Answers/@comment-37348467-20181119033620

My theory is that, when a monster loses an absorbed human SOUL (by dying, giving it up or by other means), the SOUL ceases to exist.

Evidence:
 * When Asriel died, Charas soul was (presumably) never found.
 * When Asriel gives up the 6 human souls, they aren’t seen anywhere in the epilogue. 