Dez married the then mayor's daughter and they had an infant son, who died in his sleep. He gave the body his own 'water,' and lied to his wife about their son's death. From then on, he lived a double life, as both his son and himself.
Eventually his wife died from illness. Convinced that she would have lived had she had access to modern medicine, he planned to eventually destroy the village and leave for the outside world.
As the mayor of the village, he led the villagers in abusing Phil - who eventually killed the Dez vessel once he revealed he planned to take over the minds of the rest of the villagers. Though the Dez vessel was killed, his consciousness survived in Felt's body.