Possible Clues:

• Typical Bond foe
• Villainous scientist character, say
• Villain who's both admired and feared
• Difficult-to-outsmart villain
• Supersmart supervillain
• Villainous scientist character, maybe
• Mad scientist, maybe
• One who might cackle 'Mwa-ha-ha-ha!'
• Enemy who's difficult to outsmart
• Lex Luthor, for example