Writing. I love the challenge of crossovers, trying to keep all the characters true to canon even in alternate settings.
I also like to indulge in my personal fetish for size-themed stories. Shrinking or giganticized characters interacting with differently scaled lovers.
Oh, did I miss something? I don't really recall being challenged to a duel... I'm not that stupid to take it up from someone as mighty! Well, this I will solve from concealment, then. The trade of assassins is not alien to me :]