Even though Michael was not sure if Lesser Elementals were intelligent enough to understand the language of the Origin Expanse, he gave them a fair warning. If his words were not enough, the ring's dragon might was certain to be threatening enough.
Furthermore, Michael and his people were the ones who had freed the Lesser Elementals. That should be more than enough reason for them to feel gratitude and not come to them for revenge. They were the Elementals' benefactors, not their enemies.
The Fire Elementals flared up, the flames shrouding their bodies reaching the ceiling high above their heads before they returned to their former appearance. They turned to the deeper parts of the Elementals cave and rushed inside, ignoring Michael and his people.