The Hyuman Captain wasn't dead after getting struck by a meteorite. It shook him quite, but the Divine Lifeform didn't die. He unleashed his Projectile Defense Soultrait, a 4-Star Soultrait that protected him against projectiles and survived. But then again, the Hyuman Captain would have survived without his Projectile Defense Soultrait.
He wasn't particularly powerful, and his Soultrait wasn't overly mighty either. In the first place, his lack of combat prowess was why he had been deployed as the Captain of the Hyuman Fortress in such a place. He might be a Divine Lifeform, but his prowess was more baggage than support on the frontlines.
Michael killed the Hyuman Captain and everyone else who survived the meteorite shower. He consumed their corpses using Swallow Domain and transformed them into energy and more Essences through Permute.