Doctor Doom and Galactus, to the Fantastic Four

• They're opposed
• Those at swords' points
• Pakistan and India, e.g.
• Alexander and Darius
• Exes, sometimes
• Lex Luthor and Superman, e.g
• Hostiles
• Gophers and gardeners, say
• Some are sworn

Wiktionary Word definitions in Wiktionary
n. (enemy English)