While many pokemon arrive to Stellar Central, many also use the station to take their leave - as is the natural flow of things.

The departure gate is where you can say goodbye to your recruits - either by surrendering an unwanted recruit to the crossroads, trading them in for Poke or trait applier, or permanently removing them from the game.
You may choose to send pokemon out on a local departure, a long-distance departure, or trade them in.

Local departures will add the pokemon to the crossroads pool, and their images, EXP, levels, and traits will remain intact. Keep in mind that if OC ownership is of a concern to you and the surrendered pokemon has artwork, the character and artwork attached to them can be considered as belonging to the new owner if picked up from the crossroads.
Local departures also rear a 25 poke reward.

Long-distance departures will completely remove the pokemon from the game - though artwork including them uploaded to Paperdemon will remain.

Trading allows you to take one trait from a departing pokemon; instead of a pokemon being able to be picked up by other players, this will completely void and null your roll. The trait must be one the departing pokemon has. Pokemon with just standard/no additional marking traits have the option of the standard applier OR trait remover!

Surrenders of pokemon cannot be reversed, and you cannot surrender your starter.