Ryusa was the only survivor when her pack was slaughtered by an enemy pack of wolves. She values strength above all else, so she was reluctant to join any pack that was weaker than she was. But when she got to be too lonely, he decided to seek out a pack to join.
She chose Lei'luna's pack because although they are a new pack that is just getting the hang of things, they do have the strength to be determined to make it through the rough times.
