Possible Clues:

• Fictional creature born of a post-midnight feeding
• Why the kite-flier got into difficulties?
• Bug Russian government losing head for good
• One making mischief as government's undergone change of leadership
• King leaves Russian citadel to be replaced by German troublemaker
• Mischievous creature
• Girl playing with men is mischievous one
• Girl men upset is mischief-maker
• Troublemaker Gandalf initially upset Merlin
• Troublesome sprite