Rosalina is the cosmic being who rules over the cosmos. Her role within the universe is to maintain order and protect the Lumas who live on the Comet Observatory. She has grown very fond of the Lumas and has become a motherly figure to them. She is also known for her wisdom, maturity, and kindness, which she uses when acting as a guiding figure for those who visit the Observatory. Despite her vast powers, she is known to have a sweet tooth, especially for baked goods.