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Ruri (瑠璃,Ruri?) formerly known as The Blue Dragon (青竜,Seiryu?) is a companion and contracted beast of Touya on his journey. She is one of the Four Divine Beasts and also the leader of the Dragons.
Ruri is shown to be dragon like the other Four Divine Beasts she is in a smaller form.
She is shown to have an extremely calm and rational personality as opposed to some of the other Divine Beasts.
Intimidation Aura: She is able to release a suppressing aura that renders immobile all individuals who have lower magic level in respect to the divine beast.
Long-Ranged Telepathic Communication: She is able to make telepathic communication with her master and among the divine beasts regardless the distance. She also able to include other people into this communication line.
Form Transformation: She is able to change her menacing true form appearance into cute young dragon form (Child Form) and back as she pleased.
Due to their contrasting personalities she has a somewhat difficult relationship with Kohaku.
Her name, Ruri (瑠璃), is the Japanese word for the gemstone Lapis Lazuli.