Rust is easily considered to be the cold-hearted loner of the litter. He prefers being on his own, but enjoys spending time with his family nonetheless, though he won't openly show it often. He cares very much for his siblings, his sisters in particular, and will easily willingly throw himself in harms way to protect them.
- Koji (father)
- Kaya (mother)
- Heliotrope, Charcoal, Ecru and Mantis (brothers)
- Violet, Maya and Cerise (sisters)
Rust was born at Ueno Castle and is one of the eight eggs laid by Kaya with her mate Koji. He is a hybrid between cerberus hydras and orthurian hydras. Rust is a deep reddish-brown color and has two heads and three tails like his sister, Violet.
- Rust is named after the shade of brown of the same name.