I'm not going to translate the fanfic into Japanese

The only Japanese translations are those of the Pokémon names (i.e. Panspark could be "Shokappu" while Simispark could be "Shokkie", as Pansear is "Baoppu" and Simisear "Baokkie").
Something like that; that's why there's a thread for the Japanese names of the Fakemon.