Related Clues:

• The Grays, to the Blues
• One to keep closer?
• Any Hatfield, to a McCoy
• Parley participant
• Hostile opponent
• One of them?
• Military adversary
• Scipio, to Hannibal
• Military opponent
• The Riddler, to Batman
• Hostile bunch
• Sworn enemy
• One on the other side
• David, to Goliath
• Bizarro, to Superman