Why do Leon and Ken do a ritual in "The Man to Send Rain Clouds"?

This story is filled with rituals. Small rituals—like when Louise and Teresa dress Teofilo's body in new clothes before his burial—and big rituals, like when Leon and Ken paint Teofilo's face and wrap his body. There is another ritual that Leon and Ken engage in: asking Father Paul to sprinkle holy water over Teofilo's burial site.
The reason that people perform burial rituals can vary for cultural and personal reasons. In this story, all of the rituals performed indicate respect for Teofilo. This is in accordance with the ancestor worship which many Indigenous cultures believe in. In this story, Leon and Ken perform these rituals—painting his face and asking the priest to scatter holy water—because they want the old man's spirit to rest well (and not be thirsty) and to send them rain.