Rolonia is the Saint of "Fresh Blood", one of the heroes who received the mark of the heroes of the six flowers. Her power allows her to freely control her blood as well as any blood she's touching. She's a really docile girl wearing glasses, with a hesitant and gentle attitude. Because of this, the heavy armor that she's wearing couldn't look more out of place. Her helm reminds of a cow, with horns and large fake ears.
In battle, she uses a long whip. Since the whip has her blood on it, she can freely manipulate it, allowing for extreme accuracy. If the whip hits her victim, Rolonia can drain a huge amount of blood from that victim, meaning that a few hits are usually enough to kill any kyouma, and that a single hit is usually enough to defeat a human opponent. Because her peaceful and hesitant personality doesn't go well with the heat of a battle, she motivates herself by shouting and swearing at her opponent. This is kind of a ritual for her in order to get temporarily rid of her usual personality.
Rolonia's power allows her to accelerate greatly the healing power of the blood, as well as to stop hemorrhage, making her a really powerful healer. By tasting someone's blood, she can completely analyze it. By using that power with kyouma's blood, she can even determine the special(s) power(s) of the kyouma.
Rolonia was originally a lowly servant in the Temple of the "Fresh blood" and was never part of the nuns. 2 years and half ago, when the previous Saint of "Fresh Blood" retired, a ceremony was held to designate the new Saint among the nuns of the Temple. However, the one who received the power from the god wasn't one of the nuns, but Rolonia who was washing clothes outside. When she realized that she was chosen as a new Saint, she first wished to resign immediately and all the temple of the fresh blood agreed that this was the correct thing to do. However, for this she first needed the avail of the current head of Saints, Mora, who never gave it. When Mora came to the temple of fresh blood and saw Rolonia, she saw in her a potential really strong warrior and decided to supervise her training personally.
In order to make her more knowledgeable about kyouma, Mora sent Rolonia as an apprentice to Atro, an old warrior specialized in the hunt and killing of kyouma, for a few months. There, she met the 15-year-old Adlet who was currently training as Atro's disciple, and sympathized with him after healing his numerous wounds.
As a Saint, Rolonia is a genius. Usually, Saints needs to learn how to use their powers before being able to do something, but in the case of Rolonia, she could already use the basics of her power right away, and quickly learned how to use it in really complex manners, like controlling perfectly the blood of a patient during a surgical operation.
She completely trusts Adlet and Mora, and strongly supports peaceful ways to solve different situations.