Sophitia has been in all of the Soul games, she's a veteran. So she has a long and interesting story.

Soul Edge

Greece, the birthplace of Cretaceous culture. The people's beliefs are starting to change to the new ways, but the ancient Gods live on in their arts and mythologies.
Sophitia is a tidy girl who works in a small bakery in Athens. She cherishes the mythical world of her ancestors. She often prayed to the goddess Pallas Athena, guardian of her town and embodiment of wisdom and prudent warfare. Her prayer have not been ignored.
One morning, as she bathed in a forest spring, a dazzling light shined in front of her. The light formed the shape of a man. As she stood amazed by the sight, the man told her that he was Hephaestus, the god of Forge. One of the twelve Olympian Gods.
"I'm only a mere mortal. What can I do for you?"
"Do not fear. I only want you to receive my oracle. Among all the weapons that mankind has created, one sword has grabbed the attention of the gods. The sword is true evil. It was forged blindly and now sucks up the hatred and pain of its victims. Many 'deceived' seek this wicked weapon. If any of them find it, disaster will surely follow. I will not let a creation of the forge such as this ruin my reputation. I want you to find that wicked sword before anybody else and destroy it."
The importance of this task was clear and she desired to undertake it, but still she was filled with self-doubt.
"But I'm just a mere mortal. Can I fulfill such a big task?"
"You are not as weak as you think. Obtain a mighty weapon and you can save your kind. I have heard of you from Pallas Athena. She says you still believe in the Olympians. That's why I chose you. No other except you can hear our oracles anymore. Do not worry. Come to my temple. I will grant you the best arms and Athena will always be with you."
Hephaestus then left. Silence returned to the spring. Sophitia went home and equipped herself for the journey. She left home before the rosy-fingereddawn arose. May she have the protection of the Goddes of Victory, Nike.

Soul Calibur

Following an oracle from Hephaestus, the god of fire and smithery, Sophitia succeded in destroying one half of Soul Edge.
After recovering from the wounds she suffered from the sword fragments, she returned to her life as the daughter of a baker and spent her days peacefully. However, one day Sohpitia had an ominous vision of a knight in azure armor and a sword of immense evil.
Once again, Sophitia received an oracle from Hephaestus to destroy the remaining Soul Edge. As she embarked on her journey, Sophitia held on tightly to the sword and shield forged by Rothion, her betrothed.

Sophitia's Soul Calibur story on Namco's website

When she recovered her senses she found herself lying in her bed at home. She returned to her life as the daughter of a baker and has spent her days in peace. But one day on her way shopping with her sister, she suddenly lost consciousness.
"So many lives... disappearing... Soul Edge?"
Sophitia was rescued and carried back home by a youth named Rothion who lived in the next city. Since that day they were attracted to each other so strongly that they decided to become engaged. They were visiting the Temple of Hephaestus to report their engagement to him, when Hephaestus appeared before them. The God of Smiths revealed that the remaining Soul Edge was regaining its power and he needed Sophitia's help once again.
"Let me go in place of her", insisted Rothion.
"Rothion, you are a smith, aren't you? This time it is you who will forge the armor and weapon to protect Sophitia."
Hephaestus gave Rothion a raw chunk of sacred iron and instructed Sophitia that she must completely destroy the Soul Edge. She left home with the sword and shield that Rothion had forged from the iron. She pursued Soul Edge, purifying lands seized by the Evil Seed. Her eyes shined with the light of faith.

Soul Calibur II

Sophitia was the eldest daughter of a baker. Her life was rather ordinary until the day she received an oracle from Haphaestus, the God of fire and forge, to destroy an evil sword called Soul Edge.
The divine words of Haphaestus led Sophitia on two journeys. The first time, she succeeded in destroying one half of the Soul Edge, but received grave injuries by the flying shards of the shattered blade. The second quest took place a few years later when she learned that the remaining Soul Edge continued to wreak havoc.
During the second journey, Sophitia found that someone else had destroyed the demonic sword, and so she returned home to Rothion, her betrothed. They married shortly thereafter and were blessed with two children. They led a happy life until the day they encountered a particular metal fragment.
Her children scrambled and fought violently over a metal shard that Rothion received from a mysterious customer. The evil aura the fragment emanated caused Sophitia's old wounds to ache.
"Had the shards of the demonic sword infected me with their dark energy before they were removed from my body?" Sophitia thought in horror. But that would explain her children's frenzied reaction over that piece of metal.
Sophitia's young sister, Cassandra, saw her bewildered reaction, and ran out with the metal shard. A few weeks passed before Sophitia made up her mind.
Sophitia intended to free her children from the evil sword's curse and insure the safe return of her sister, who had left on a journey to destroy Soul Edge on Sophitia's behalf.
In Sophitia's hands were the new sword and shield that her beloved husband had forged for her.

Soul Calibur III

In order to save her children, Sophitia embarked on a journey once again. Following the rumors of Nightmare, she arrived on the bank of the Rhine river, overlooking Ostrheinsburg Castle.
Breaking the silence, a small girl in dark green clothes suddenly appeared from the mist and spoke to her with an innocent smile. Sophitia remained on guard and drew her weapon. She could tell that the unusually large ring the girl carried was a weapon.
"Soul Edge isn't in that castle anymore. Say, I'd really like to play with your children." the girl said.
Sophitia attacked without a word, but the girl dodged the blow, disappearing into the mist with a twisted giggle. Sophitia hurried home and was relieved to find her family safe. She could not relax, however, for she did not know what she should do. Feeling uncertain, Sophitia headed to the temple of Hephaestus, God of the forge. But what awaited her at the temple was none other than the girl in green. Sophitia quickly picked up her sword and shield.
"Ahaha! You want to fight me? Sounds like fun!" The girl in green beamed. Blocking the girl's attack, Sophitia looked into her eyes and saw the emptiness the girl held in her heart.
"Poor child. You've never known happiness..." Sophitia murmured. The girl froze. Her expression changed from her previous fake smile to a look of extreme hatred. She knocked back the surprised Sophitia and took her distance.
"You're annoying... when the time comes, I'll come for your children."
For the sake of protecting the ones she loved, Sophitia steeled her resolve to eliminate the threat at the source. She announced her intentions to Rothion and once again put on her traveling clothes.
"You be careful..." Rothion softly said to her.
In the eyes of this woman, who believed in herself and fought her those she must protect, shone a light of hope that would illuminate the future.

Soul Calibur IV

Sophitia continued her pursuit of the cursed sword and at last she arrived in the sword's dominion, Ostrheinsburg. There she learend a shocking truth. While she was away from home, a cunning servant of the cursed sword had abducted her daughter. Soul Edge had grown more powerful than ever, a sinister voice whispered, and her young daughter would die without it's evil energy to sustain her.

"Feeling torn? I would, too, if I'd left my children to fend for themselves!" The words clung to Sophitia like a curse. "Well, don't believe me, if you don't want to, but I suggest you think carefully before making your choice." She had come running after the sword to destroy it, but when she thought about the consequences now, if Soul Edge should be lost, what would become of her child?

And so that her child might live, the crusader Sophitia made her choice; to battle any warrior who came to Ostrheinsburg seeking to destroy Soul Edge. With each new sin, guilt tore at her heart, but there was no other way. Would Sophitia and her family never be able to dwell in the light of the sun again?