Puzzle from one of my games

This is a puzzle that I created from a game that I played in a thematic tournament.  The game did not finish with the puzzle line, but I think I have improved upon the defense my opponent played.  Just as a final note, I messed up when making the puzzle, and so, for black, there is an extra knight on b8 which shouldn't be there.  It doesn't factor in the puzzle, so just try to ignore it.