Minihouse Puzzle #1

Black to move. I lost -19.1 just because I got it wrong.

Rook b3?

RxN definitely
if NxB then @N fork
if RxB+ RxR NxR KxN the position is unclear

I did KxN XD which resulted in the rook

But if RxN, can't white place a Bishop on e5 and win?

White can drop a Knight fork

One more line: RxN Kc5 Rxd6!! Kxd6 N@g6

RxN RxB+ seems critical to me, black is probably losing anyway