Deathstroke: I believe that white still had a game after 36.Nxf6+. I'm just examining this by eyeball (no computer analysis), so I can't be certain. But I see the following key lines:
36...gxf, 37.Qd5+ Kg7 (Kf8 loses rook to Rh8+), 38.Qf5 hitting the h7 square for a skewer, and the rook on c8.
36...Kf7, 37.Qd5+, KxN, 38.Rf5+, Kg6 (Ke7 loses to Qf7+), 39.Qe6+, Kh7, 40.Rh5#, so the knight is poison for the king.
36...gxf, 37.Qd5+, Qf7, 38.Rh8+ leads to either perpetual check, or white trading his rook for black's queen. This would still leave black at a severe material disadvantage. Indeed,
black's cluster of pieces on the white-queenside is unassailable... but it's also extremely passive. I believe this line lets black take advantage of this to pull a draw out of the fire.
There are many other lines that I haven't mentioned here, but I think many of those lines gives white the best chances for a draw by perpetual check. Given his serious lack of material, that should be his goal at this point.