As the title states, I want to suggest a feature that lets you make a Pokemon become untradeable. Similar to shiny pokemon, there could be a tiny subtle logo that indicates when a pokemon is untradeable in a player's party.
Maybe it can be added in the pixelmon editor as an option in "Form" or add a new option "Trading", "Tradeable" or something along those lines.
If a command were to be added, maybe /pokelock, /poketradeable, /ptradeable (Maybe theres a better way to make it work idk xD)
While we're at it, maybe even make it unbreedable (sterile? lol) or add an option for that too. The main suggestion is the untradeable Pokemon.
It would make the pokemon a lot more exclusive to the player.