[Scripting Question] Creating a new Battle System

I been trying to experiment on replicating a battle mechanic that I seen in Pokémon Prism, in which there is a some cases where the player can send their Pokémon into an area that the player themselves can't enter, and so the player takes control of the Pokémon as if they were controlling the player in the overworld.

If you get into a wild encounter, it will instead display the Pokémon you are controlling in the player position and the wild Pokémon, to which then it skips having the player sending out their Pokémon as they are already in control and will instead play its cry, to which then it displays a unique command box with the options to Fight, Guard, Team, and Run.

Fight opens the movelist and is still the same as normal battles, Guard will have your Pokémon guard itself, much like in traditional RPGs where you will take less damage from the opponent's attack, Team opens the Party menu and Run lets your run away.

Because of this, you are unable to use any items since you don't have access to the Bag, so healing can only be done if you are holding a Berry.

Now, I want to if it is possible to replicate this sort of battle system by having it called out if the Pokémon is being controlled as if they were added in the metadata PBS as another Player character?