|Origin||Monster Rancher 4|
|Game(s)||Monster Rancher 4|
Rio is your 16-year-old assistant in Monster Rancher 4. The adopted daughter of Cesare, the Togle shrine master, Rio possesses the unusual ability to talk to all monsters in their native tongue. One of her best friends is Mockruji, a large type of Mock that lives on your ranch.
As the story progresses, we learn that Rio is actually a long-lost princess from the beginnings of the ancient war, whose father called on Suzaku to save her when she fell ill. The kind Phoenix gave her his blood, which healed her and granted her the ability to communicate telepathically with monsters. Before the creation of Moo (and the events described in the Monster Rancher anime series), a Dark Lord named Xevion tried to take over one of the continents, and was only defeated by this princess, with the help of the legendary Phoenix. This is part of what precipitated the war of the Ancients, and the Phoenix sealed Rio inside a mystery disc to keep her safe.
Hundreds of years later, Cesare found the tablet and unlocked Rio, who had reverted to being a baby. Since the events of the anime series, in which the Phoenix was resurrected twice, its soul came to rest in several ancient relics, called Gaea Stones. During Monster Rancher 4, every time Rio is near a Gaea Stone she has a vision of the past, accompanied by violent headaches. She even blacks out during one the tournaments, and her visions eventually lead you to the person responsible for making mechanical modifications to monsters. It turns out he has been looking to release Xevion all along, and once he does, it is up to you to defeat the Dark Lord.
That land-dweller, whose happiness was left for another age. The adorable one whose voice soothes all, who brings the hearts of human and beast together in harmony. The one who is human, but not human.
-"Healing Child" MR4