MY FIRST EVER BRILLIANT MOVE

Bxc6, sacrificing the bishop to tactically win the rook on a8. If Nxc6, then Rxa8 will not just win the rook on a8, but will skewer the king to the rook on g8 as well! If Nb8 or Nd8, Rxb8 or Rxd8 will also skewer them and win the knight as well! If king moves, Rxa8 will win both rooks as the bishop on c6 defends a8!