first season, 5th episode rudy comes in, initially a friend (brother) and in the
end dexter slices him up (8 episodes total).
second season, 3rd episode lila comes in, initially a friend (lover) and in the
end dexter slices her up (10 episodes total).
third season, 3rd episode miguel comes in, initially a friend (colleague) and in
the end dexter slices him up (10 episodes total).
well, who knows. the others weren't introduced as 'bad guys' either though, they
just turned out to be. surely if they intend to do the same with miguel, they
would describe him as a good guy for now. i hope it doesn't happen, because it
really would be too predictable.