fight gym leaders that are weak against your type
train them
Struggling at the gym and battle maison
no omega is not a real pokemon, but arceus is considerd the omega pokemon.
You could train in Victory Road. It has the highest leveled pokemon. Thanks very much.
give the Pokemon you want to train an exp share then put your strong Pokemon first on your team and train on high leveled Pokemon the Pokemon with the exp share should level up by itself!
go to trainer to utot train do yo want to train uutot kanalan
you can only find it during swarms
Give your Pokemon a Rare Candy,or give it an Exp. Share and train.
trade them to heartgold
you can't find omega
Illumise in Pokemon Omega Ruby can be caught in Zorua at the park.
It is called Love Train