Niantic is cleaning house in Pokemon Go by deleting Pokemon obtained by illicit means.
On Twitter, Niantic announced that it would be taking measures to make the game “fun and fair” by countering third party services that players can use to cheat. In this case, Pokemon caught using such services will be deleted and replaced by a red diagonal line, as a mark of shame in your Pokedex.
These Pokemon can’t be used, making them useless. One Twitter user helpfully shared what this looks like:
It’s possibly a countermeasure being put in place before the arrival of Pokemon Let’s Go Pikachu and Eevee, Switch games that will allow the transfer of Pokemon from Pokemon Go to the new titles.
Pokemon Go is set to get an influx of fresh critters with the addition of Sun and Moon’s Alolan pokemon. Alolan Exeggutor dropped this week, and the silhouettes in the announcement image indicate that Alolan Diglett, Meowth, Vulpix, Raichu, and Rattata are also on the way.
You can check out the full list of Alola form Pokemon in our Pokemon Sun and Moon wiki.