the proper way to play johnny is to pressure constantly, and end everything in nut punch
my main bnbs are
2, 1, f+2, dash, f+3, nut punch
b+3, dash 2, dash 2, dash 2, 4, 4 nut punch
f+4, dash 2, dash 2, dash 2, 4, 4 nut punch
air to air you can either 1, 1, dash 2, dash 2, nut punch
air to air if theyre close to the ground f+3, nut punch
neutral jump, dash 2, dash 2, dash 2, 4 4 nut punch
corner is easy 2, 1, f+2, 2, 2, 2, 2, 2, 1, 1, 4, nut punch
off an xray dash b+3, 2, 1, f+2, dash f+3 nut punch
johnnys best block strings are f+3, 2, nut punc if the 2 connects if not repeat f+3, 2 or you can 1, 1 or f+3, 3