There are a number of mythological creatures involved in this story, many of which have my own artistic interpretation. Here's a brief list and description of these.
Eastern dragons are inspired by art of dragons featured in Chinese and Japanese mythology. In this story there are four clans or "species" of dragons based on the four major elements: Earth, Fire, Water and Air.
Characters: Ryuu the Dragon Lord (water), Queen Kimiko (Fire), Osamu (Air), Jiro (Air), Pearl (Earth)
Traits: Natural Shape Shifters, can perform powerful spells based on their element, Immortal unless slain or cursed.
Dragons of the west include Wyverns, Red Welsh Dragons, and Green Dragons. Their distinction is mostly based on location as all dragons are fire elementals of a sort.
Characters: Lady Sieghild (Red), Katsuro (Red), Guests (Green)
Traits: Flight, Immunity to Fire, Fire breath, long-lived (thousands of years.)
Unicorns are inspired by the western version of the myth, making them one horned horse-like creatures. These are creatures of purity and healing. They are easily drawn to pure-hearted virgin maids.
Characters: Lady Moriko, Guests
Traits: Natural Shape-shifter, can perform miraculous healing, cure poison, have a sort of hypnosis, immortal unless slain
Kirin in this story are inspired by the more deer-like interpretation with mostly unicorn features with dragon scales down the back and claws for their forelegs. They are a cross of eastern dragon and western unicorn in this story.
Characters: Yuuto (water element)
Traits: Natural shape-shifter, can perform some spells based on an element, minor healing, dream-walkers, immortal unless slain.
There are a large number of "animal spirits" which is an umbrella term for many types of creatures from half-animals to talking animals. It can refer to deification of an animal based on local lore of various cultures. In this story these include, tigers, rabbits, foxes, snakes, spiders, and coyote.
Naga are half-human, half-snake from Japanese and other cultures lore. In this story, they are Indian inspired.
Traits: Long-lived, poisoned fangs
Kitsune are from Japanese mythology being shape-shifting fox spirits. In this story there are several clans of kitsune based on coat color and location. They are capable of performing ritual spells but their ability is based on the number of tails with the maximum known being nine. In the story there are two major clans featured: Snow Clan and Silver Clan. The Silver clan is currently the major power.
Characters: Princess Michiko (Silver), Goro (Silver), Aki (Snow)
Traits: Long-lived, natural shape-shifters, able to perform ritual spells, illusion magic, foxfire magic
Phoenixes are based on Chinese myth of the flame-based reincarnating bird. They live long lives and burst into flames at the end of it. A new Phoenix rises from the ashes. In this story Phoenixes can only reincarnate a certain number of times before they reach final death.
Traits: Immunity to fire, Flight, Reincarnation Magic, Incredibly long lived.
The Faerie or Fair folk encompass many types of tales from European myth including fae, elves, sprites, brownies, gnomes and others. The two fae courts Seelie and Unseelie are present in this story. The Seelie are currently in a position of favor.
Characters: Lord Xavier, Guests
Common Traits: Immortal unless slain, can use glamour/illusion magic, can perform ritual magic and spells
From the Scottish myth, this cat shape-shifter was often thought to be an agent of death. Technicaly the sidhe are part of the fae family with some mild differences.
Characters: Lucky, guests
Traits: Can reincarnate 9 times, natural shape-shifting
Sprites are some of the lowest forms of fae with just enough intelligence to get them in trouble. Often small in size but able to perform incredible feats if they can be directed to do so.
Characters: Kichiro's helpers
Traits: Short-lived, can perform spells, prone to command spells, incredibly strong for their size
From the Middle Eastern myth, the djinn are morally ambiguous spirits of the desert. They are powerfully magical and quite dangerous to confront without protection.
Traits: Immortal unless slain, can perform powerful spells, natural shape-shifters