During big fights in the arena or gladitorial ring between two well known or important warriors. When one looses and dies, the crowd throws copper coins into the arena for the slain warrior to take with them on their passage of death. This is to make their passage and afterlife richer and less troubled. It is a sign of respect.
If you want to add a "supernatural" touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.