It seems to me that 1. Nd6 is the solution. The following answers are possible:
- 1....Nxd6 2. Ba5 and mate on c7 is following
- 1...cxd6 2. Qc2 (threatening Qxc8 or Qc7 mate) Nc5 (blocking) 3. Ba5 mate.
- 1...exd6 2.Qf6 Re7 3.Qxh8 Re8 4. Bh4 mate.
- 1...Ref8 2.Qe8! Rxe8 3.Nf7 mate.
- 1...Rhf8 2.Qxe8 Rxe8 3. Nf7 mate.
Cool! You found all the necessary key variations to complete the solution. Congrats for being the winner of this round! :)
Me gusto mucho, éxitos!!!
Nice to read that you enjoyed my chess riddle! :)