Yui is a young girl from Fomoire Island. Born in Olíndic Family, she inherits the power of the Legendary Beast.
She is one of the Six Ovates but has the lowest status among them.

She has a younger twin sister.
Though she seldom mentions her sister, she seems to love her sister dearly.
She is being quite protective of her sister. Once someone suspicious comes near, she will lift her spear without hesitation.

As an Ovate, her responsibility is to guard the Island and wipe out any intruder.
To be as powerful as other Ovates, she followed Flare, the Priestess of Irminsul, to train herself.
When the training is done, she becomes a master in the family spearplay skills passed down through generations. Not only that, but she also became proficient in all kinds of conjuring.

When in combat, she stabs at the enemy with a conjuring-converged spear
Meanwhile, she summons the Legendary Beast, which can enhance the strength of her body.
"The Demonsbane Spear is not sharpened to slay evil, but to bring peace to this world."