Dazzlings

The Dazzlings are the main antagonists in My Little Pony Equestria Girls: Rainbow Rocks.The group consists Adagio Dazzle and her bandmates Sonata Dusk and Aria Blaze.

In Rainbow Rocks
The Dazzlings are first seen in a cafe at the beginning of the film, feeding on the negativity caused by its patrons. There they witness a blast of Equestrian magic coming from Canterlot High School and decide to exploit it to get everyone in the human world to adore them.

Upon enrolling at the school, Sunset Shimmer gives them a tour and informs them of an upcoming musical showcase. During the tour, Sunset gets a bad vibe from the girls, later noting "something off" about them to her friends. Not long after, the Dazzlings appear before the entire student body in the school cafeteria and convince them to turn the friendly competition into a Battle of the Bands. As a result, they turn everyone against each other, with the exception of Sunset and her friends, and even entrap Principal Celestia and Vice Principal Luna in the web of their spell.

It is later revealed through Twilight Sparkle's research that the Dazzlings are sirens from Equestria who long ago used their music to cause disharmony among ponies. Eventually, they were banished to the human world by Star Swirl the Bearded for their actions.

Throughout the competition, the Dazzlings draw the students and faculty in deeper with their siren songs and advance to the final round. They also convince Trixie to forcibly remove the Rainbooms from the competition by trapping them under a stage. Before the Dazzlings are able to grow powerful enough to rule the human world, the Rainbooms defeat them through the music of friendship and destroy their gem pendants, breaking their spell on the school and rendering them unable to sing.The students booed,and throw vegetables forcing the to leave in disgrace.