I want to breed my lucario with a ditto in omega ruby to get a riolu egg, but I want to know if it is even is possible to do that since my lucario is male. (My native language isn’t English so apologies for any possible bad English)
Pokémon in this Egg Group have the unique ability to breed with any member of every other Egg Group, except for the Undiscovered and Ditto Egg Groups.
Male Pokemon are not one of the exceptions, so Ditto can breed with males. source