A shifter is someone who can shift gravity in different directions thanks to an animal-shaped being which resembles a night sky due to their starry black skin. Kat and Raven are the only known shifters. Each one of them has their own animal, Kat's being a cat which she name's Dusty, and Raven's being a crow which she name's Xii. These cosmic animals are named the Guardians. Only members of the ETO royal family can possess them. Cai is also revealed to have a guardian named Wolp, which resembles a deer with wings. This makes Cai the third shifter known.