Related Clues:

• Tough rivals
• Luthor and Zod, to Superman
• Agents of undoing
• Fearsome foes
• Tough opponents
• Joker and Riddler, to Batman
• Harry Potter and Lord Voldemort, e.g
• Effective banes
• Sinestro and Professor Zoom, in their respective universes
• You can't beat them
• Watch people on the up eclipsing second greatest rivals
• Usually victorious rivals
• Sworn enemies
• Rivals who often win out
• Superheroes always have them