Possible Questions:
- Ruins
- Rivals
- Formidable opponents
- Thorns in one's side
- Waterloos
- Unbeatable opponents
- They can't be beat
- Avengers
- Arch enemies
- Agents of retribution
- Usually unbeatable rivals
- They're unconquerable
- They're unbeatable
- The Steelers, to the Ravens
- Superheroes, to villains
- Holmes and Moriarty, e.g.
- Formidable rivals
- Banes
- Archrivals
- Archenemies
- Unbeatable rivals
- Unbeatable archenemies
- Tough rivals
- Tough opponents
- Those imposing retribution
- They give comeuppances
- They can't be beaten
- The Ravens, to the Steelers
- Rivals to who one always loses
- Plan foilers, perhaps
- Luthor and Brainiac, to Superman
- Like Batman and Robin to the Joker
- Inflicters of retribution
- Formidable foes
- Fighting types
- Bond and Blofeld, e.g.
- Batman and Superman, to villains
- Batman and Robin, to Catwoman
- Archenemies, maybe