Juan Diego de la Muerte was born and raised in Whittier, California. He became fascinated with Aztec mythology and the Dia de los Muertos (""Day of the Dead"") traditions in Mexico. Raised Catholic, Diego often wondered what the Aztecs thought when their religion was replaced with what the Spanish conquerors believed. On his 21st birthday, Diego is excited for an upcoming Dia de los Muertos festival. Unfortunately his friends could not join him and Diego was forced to go alone. Borrowing his friend's car, Diego is dressed as an undead Mariachi. To celebrate the occasion, he got a tattoo of an Aztec skull days earlier. Unknown to him, the skull is actually a symbol of death representing the Aztec death god. The car crashes into a tree, killing Diego. He later wakes up in the land of the dead, Mictlan, where the Aztec gods Mictlantecuhtli and Tezcatlipoca sacrifice him. His heart is removed, and his facepaint is burned into his skin. He is told that he must fulfill an ancient prophecy and is sent back to the land of the living one year after his death. After he learns that he is truly dead, he finds out he has supernatural powers and decides to use them to help people.