Lachesis Valkyrie (Ingrid Målmann, the later years)

After the events celebrated on the holiday, Revelation Day, in the world of Athena Minerva, the woman later to be called Saint Ingrid took control of her husband's fighting forces and, through a series of "good deeds" which some philologists liken to the twelve Labors of Hercules, grew it into a large (for the time) navy and confederation of land armies.
Saint Ingrid, known by the Norse Vikings as "Valkyrie, Chooser of the Slain", led the force to fight a yeti, several catoblepae, a dragon, sea creatures, and a giant gorilla, increasing her followers and "magical" technology every step of the way.
Not the climax of her story, but the largest naval battle of her career was known as the Second Battle of Athens, which legend states was fought by Athena and all the armies and navies of Athens against an embittered Poseidon, still sore from losing the first battle, and his amassed forces on the floating city of Atlantis.
When she learned of the impending attack, Valkyrie used her advanced ship technology and racing skill to outrun the Atlantean armada and arrive in Athens first. After an initial standoff, she managed to win enough respect to garner a parley with the goddess Athena in the flesh (in roughly A.D. 1000, long after the general population considered her to be just a metaphor) at one of her few still-standing temples, filled with star-struck mortals. Athena immediately believed the story of Valkyrie's discovery of the approaching island of weaponry and Poseidon's grudge. Valkyrie and her troops relayed the strengths and weaknesses of the Island of Atlantis which they had seen with their own eyes. Athena and Valkyrie plotted their strategy in a few hours.
With only one night before Poseidon's arrival, Valkyrie's men showed the sailors of Athens a simple modification to the keels of their sailboats which greatly increased their speed and maneuverability. Weapons were loaded with the speed of desperation. If Athena said Poseidon was coming to attack the city, then it was true in the minds of every able-bodied inhabitant.
On the morn, the fortified city of Atlantis sailed in (against the tide flowing out) and entirely blocked the largest port of Athens with its girth. Expecting exactly that, sailors launched from beaches where they had moved their vessels under cover of darkness the night before. The fishing boats recommissioned as warships pummeled the edges of the floating city and boarded in a few places while Valkyrie's ships deposited divers into the underwater mechanisms that acted as powerful oars to propel the city. Though Atlantis' massive main cannons toppled many towers in Athens and breached one of its defensive walls, and a beam of heat from the front of the sea fortress set aflame many soldiers, it was less than an hour before Valkyrie's forces wrested partial control of the floating fortress from the denizens of Poseidon and turned the massive flotilla to aim the most powerful weaponry to the sea.
On the port and beaches, the infantry battle raged. Even out of their element on firm ground, the tritons and warrior mermaids of Poseidon's army exceeded the strength of the mere mortals of Athena's army of male and female warriors, and the gigantic stature of Poseidon leading the charge was unmatched... until... Poseidon was confronted by Valkyrie, who had been employed by Athena the night before to locate in a dungeon far beneath Athens the still living high priestess of Athena who ages ago had been cursed for exceeding her station. Valkyrie then (barely arriving in time) unveiled High Priestess Medusa to Poseidon. In moments, even the powerful Poseidon in this gigantic (yet all too human) body succumbed to the "beauty" of Medusa's face.
The last of Valkyrie's fabled battles was against an inhuman army of monsters and their creators, but with the assistance of her allies (with the army and navy of Athens among them), she managed to end the age of the legendary man-eating beasts and allow Earth's history to return to what she claimed was the correct history, with humankind once again at the apex of the food chain.
(See the holiday, Revelation Day)
(See Medusa, Not Safe For Work, NSFW, Rated R-NS for nudity and sexual activity)