The phrase "descended on" can be described using other words to convey the same meaning. Some synonyms for "descended on" include: swarmed, inundated, converged, besieged, gathered, flocked, congregated, mobbed, hassled, or converged upon. All of these words suggest a large and sudden gathering or a large number of people or things in one place. It could be used to describe a sudden rush of people to a store during a sale, a group of fans arriving at a concert, or a horde of insects descending upon a crop. Synonyms for "descended on" can help add variety and depth to one's writing.