The Elf Frozen for Thousands of Years

Her identity was unknown, but she was rescued by someone. In order to pursue the mystery of the death of the elves, she transformed into a man and entered the desert, facing the strange quicksand and surviving. However, she arrived in another world: a world composed of demons, humans and demons; She is powerful and her identity is unknown; however, she can make the flower of hope bloom that has not bloomed for hundreds of years, and she can use the purple light sky array to compete with the demons; she can make the demonized bloodthirsty elves fight to save her; what is her unknown identity?