Yea ik I have been told, you just have to run with your loomian as your main in your party, fight with it (takes a bit of time so you have to be patient), sometimes might have to be max lvl (my eleguana got ecstatic when i was battling with it when it was max lvl but not always that they have to be max lvl). SO basically it just takes time and you have to probably wait for the right time.