Does Galarian Slowbro's shell side arm actually become a physical attack if the opponent is weaker to it and scales off of your attack stat? Or does it stay a special attack but damage the target's defense stat, like psyshock?
Shell Side Arm forecasts whether its base damage would be higher as a physical move or special move, and becomes the category that it predicts would inflict more damage (chosen randomly if they are tied).
So it deals damage either as a Physical or Special Move, using the according Defensive stat. It's kind of like Photon Geyser with it being a Physical or Special move.
Source: https://m.bulbapedia.bulbagarden.net/wiki/Shell_Side_Arm_(move)
