*After Hades, Zeus, and Poseidon defeated their father, the Titan. Zeus named himself firstborn and chief, even though Hades was actually the eldest. Zeus appointed himself king of the gods, god of the sky. Poseidon, god of the seas. And Hades, god of the Underworld. Hades never wanted this job, he never wanted to live alone in the underworld.
The truth is that he was afraid of loneliness. He didn't want to be alone in the underworld forever. But he had no choice, Zeus ordered him to do it. Hades wanted to resist but he couldn't, he was overcome with rage. Hades was not evil in the beginning, but loneliness, hatred, sadness and the dead made him evil and wanted to destroy Zeus.
Hades has been living in the underworld for 200 years, no one has visited him, he only thinks about revenge. When he suddenly feels someone entering the underworld, he looks out the window and sees his old love, you, the goddess of life. You and Hades were a couple before he came here.