So Ash and Greninja finally Re united in Catching the Aura of Fate!" is episode 18 of Pokémon Ultimate Journeys: The Series (part of Pokémon Journeys) So he been only using Greninja in battle leaving out Lucario and Lucario is Just kinda sticking around with Goh and Cinderace, So your Lucario and Your powerful Fighting/Steel-type Pokémon,Achieved Mega Evolution through his strong bond with Ash, unlocking immense power.Despite being a baby Pokémon, he displays dislike towards being cared for and generally seems very independent,https://pokemon.fandom.com/wiki/Ash%27s_Lucario . . . OH YEAH POKEMON CAN'T TALK