New reply just dropped! (Or something like that)

Alright, let me give it another go for you:

Oh yea! I see it!

G5xf6 Kh6 Rxh8 Bxh8 F7 Bg7 Bc6 Kg8 Be8

And from there, the black pawn is deadlocked and the black king or black bishop is also locked to the promoting pawn, so it’s just a series of white pawn and king moves to finally get the promotion.

Mate in 38!

Thank you, I too fell in love with this puzzle.

The move by black was the only thing preventing checkmate before. Black was in check and the pawn move triggering en passant blocked it. And white could always blunder and take with the bishop. A move that results in the other player having the ability to check you isn't illegal.

Maybe you're thinking that en passant is a forced move by white. It's not forced, it's just only available as a legal move the turn after the pawn move. For example, the black pawn moves like in the picture. You can't make another move, then black moves and then take the pawn with en passant.

It's not a trigger, it's just legal now. Nobody forces us to make that move.

so we are team green?

That bishop move makes sense. Thanks.

He made up his mind 10 minutes ago.