1) Make a list of twenty-one characters/people first, and keep it to yourself for the moment.
2) Ask your flist to post questions in the comments.
For example, but not limited to:
'1,9,15,and 21 are chosen by a prophecy to save the world from 4. Do they succeed?'
'Under what circumstances might 5 and 7 fall in love?'
'Which character on the list would you most want on your side in a zombie invasion?'
'What Pokémon would 8 have?'
'Write a drabble in which 16 and 19 FIGHT CRIME.' (...possibly not technically a question.)
3) After your flist has asked enough questions, round them up and answer them using the twenty-one characters people you selected beforehand, then post them.
So loves~ Ask me some questions :3