Perhaps he had some success with it in the past? The move is pretty dubious because there's not enough compensation for the sacrificed piece, but at least he could have followed up with more aggressive moves to make the situation more complicated for white.
Also, 8.Nxe5 would have won the piece back for black.
I didnt understand why he gave his bishop up for a pawn when I can easily make a "fake" castle, which I did.
Perhaps he had some success with it in the past? The move is pretty dubious because there's not enough compensation for the sacrificed piece, but at least he could have followed up with more aggressive moves to make the situation more complicated for white.
Also, 8.Nxe5 would have won the piece back for black.
24. Rc8 Rf8
25. Rxf8#