The following rules are from an out of date rule-set
There are five basic types of Ryú. Each has become a symbol of the realm they tend to inhabit, sacred to its people. Killing a Ryú of your opposition is a common condition for victory in war in Engoku. Indeed, it was thru slaying a dragon in each realm that Nippon gained dominance in Engoku. Despite this tendency, each type is found throughout the Five Realms. There are even a few unique Ryú flying about, unlike any of their elemental counterparts. Ryú are, for the most part, benevolent to mankind, particularly the wise and kind. They are quite intelligent; prone to doing great deeds for the pure and suffering terrible misery untothe wicked.
Ryú are huge, flying thru the sky unaided by wings. They have a very serpentine appearance, except for their arms and legs. They usually have long, fiery moustaches, eyelashes, and sometimes beards. Most live in Mountains Terrain, even if it the mountain is underwater.
Ryú Mount Option: At some point, players will want to use a Ryú for a mount, either for a large Quest or dramatic aerial combat. If so desired, and approved by the reeve, Ryú may be given the Greater Mount Trait. All players should be made aware if this option is used in a battlegame. Keep in mind, players mounted on flying creatures may engage in melee with other flyers, avian mounts and their riders as well. Note: going into melee against a Monster with Natural Siege Weapons is not a really good idea.