Here is the complete solution:
Congrats to @juanmi96 as winner of this round!
1. Nc3!
a)
1. ... Bxc3
2. Bd3+ b5
3. axb6 en passant # (checkmate)
b)
1. ... Ne5 (covers d3)
2. Bc8 Bxc3
3. Rd5! c1Q
4. Bxb7# (checkmate)
c)
1. ... c1N (the best black try, covers d3)
2. Be6! (threatens Bc4#) Ne5 (covers c4, but prevents its own bishop to give check at e5 later)
3. Bc8 Bxc3
4. Rd5 (prevents blacks king to escape via b5) Bxb4
5. Bxb7# (checkmate)
Very elegant how the knight move to c3 prevents a check in case black underpromotes his pawn to a queen and at the same time closes the possible exit path via b5. Also the following moves are really tricky.
arrrggghhhh not fair! I was trying to analyze then I saw this below!
arrgggg.. thanks for putting it up here haha
haha i second this, soon as i jumped in like yaay i will solve it, found the solution below, excitement killinng comment :D