Possible Clues:

• Took case of euphoriants in place of spirits
• He was accompanied by the guard dog Cerberus
• Underworld king in Greek myth
• 5-Down's realm
• Flame-haired villain in Disney's 'Hercules'
• Flame-haired villain in Disney's "Hercules"
• Brother of Zeus
• Realm of the departed, headless ghosts
• Underworld, in Greek mythology
• Such a destination includes Pluto