Recently, I recommended a player to start with the random battle to farm chests, pvp coins, etc. But since he didn't have a pokedex made, he couldn't guide himself by anything, he didn't know the status of almost any pokemon or any ability, I know he could use it in the browser/smogon, but what if this player played on his cell phone for example?
With that in mind, I suggest that you temporarily release your opponent's Pokémon in the Pokedex to help players play their matches, especially unofficial Pokémon. For example: Baby Lugia, XD001, Mewtwo Steel.