I recently platted the game on Vita. For me Grundy is very good for The Max. As for Impossible! I would get rekt over and over by the 11-12th fight so I switch to Doomsday. Using Doomsday I used the combo J, D3, 1,2,3, df3(sometimes amplified) doing the jump while crossing over the A.I seems to mess them up. As for Grundy and the Max would prob be easier in PM since I do things a bit differently with him. My Grundy isn’t good but was able to do The Max twice on Vita