That's a creative solution! Here is how I was thinking just FYI.
I wouldn't use atan, as you have an extremely slim chance to divide by 0 and I'm not sure how C2 would handle that. Maybe there are safeguards built in and it would be ok, but I'm not sure. Use the angle() expression instead.
I was thinking would be to set angle , then use the action move forward based on distance, or just move at angle.
(I'm assuming axis 0 is x and 1 is y, swap them if I'm wrong)
Angle = angle(0,0,gamepadaxis(0,0),gamepadaxis(0,1)
Distance = distance (0,0,gamepadaxis(0,0),gamepadaxis(0,1)
Optional - Multiply distance by a speed multiplier.