A lone mage named Siluca and a vagrant knight named Theo make an oath as master and retainer, with hopes of bringing reform to a land riddled with war and chaos.

With Theo now in control of his own territory, Siluca starts putting plans into motion, as well as calling on old allies. Meanwhile, in the neighboring region of Savis, an ambitious Lord plots to overtake the fledgling kingdom.

Now with Lassic in the fold, Theo’s forces are routing the free Lords of neighboring territories left and right. At Siluca’s suggestion, he decides to assume the name Cornaro, after a hero from his homeland of Systina. But far from becoming a household name, Theo is instead rumored to be a mere figurehead. It is then that a town in Theo’s village is struck by Chaos Disaster. And a fiery Salamander assaults Siluca!

To make their case for joining the Alliance, Siluca heads to Valdrind, ruled by Marrine Kreische. But the talks don’t go as smoothly as she’d hoped. Siluca’s next step is to seek an audience with Union member Villar, the Earl of Artuk, but she’s unceremoniously turned away.

Pledging to serve Villar, Theo heads to Artuk with Siluca. The first task Villar gives them is to govern the Forest of Eternal Darkness, a territory ruled by vampires. When Theo and Siluca head to the forest, they see the shadow of an ominous-looking woman...

Villar's Mage Leader, Margaret, is about to turn 25. Villar only employs female mages, and when they reach the age of 25, he has their contracts voided. A lavish party is thrown. All in attendance express their gratitude to Margaret, as well as their sorrow at having to bid her farewell. It is then that Villar takes her hand and asks her to dance. Siluca looks on with growing frustration as they dance passionately, almost flaunting their mutual feelings for each other.

A conference between the Lords of the Fantasia Union is to be held. Villar orders Theo to capture a fortress city ruled by the independent Lord, Ladvan Toriuss, widely known as a man of sincerity, and trusted by his people. What kind of strategy does Theo deploy to defeat such a man?

The Great Hall Tragedy… If only that incident had never come to pass, Alexis Doucet and Marrine Kreische would’ve have been united in marriage. Six years ago, they fell in love in Eramu, Their feelings never changed even though they were aware of their respective positions; the Fantasia Union and the Factory Alliance would’ve become one, thanks to true love. But those hopes were soon shattered. Now having assumed their fathers’ leadership roles, they find themselves at a crossroads once again. Peace, or war. Which will they choose, and what lies ahead?

The Fantasia Union seeks to broker peace, but the Factory Alliance opts for battle. When Starck attempts to secede from the Union, Marrine mercilessly sends her troops to attack. Siluca recommends supporting their neighbor, Starck, but having pledged loyalty to Alexis, Villar is steadfast in his refusal to do so. In fact, he orders Siluca and Theo to leave the castle.

After subjugating Starck, Waldlind barely pauses before invading Altirk. Villar joins forces with neighboring domains Kilhis, Regalia, and Haman to repulse Waldlind, but then a new enemy arrives from the seas. It's Milza Kuches, price of Dartania, who once looked up to Villar. Milza has forsaken Villar, instead becoming Marrine's sword. And with the Dartanian fleet in tow, he's about to unleash a furious assault on Altirk.

Despite suffering casualties, Altirk has gained the upper hand in the battle. But suddenly, a massive fleet is spotted, advancing towards them from across the seas. Marrine has called on Nord, the nation across from the continent, to reinforce her troops.

Even after Villar is killed, the Altirk Lords continue to fight on. Gathering at Lassic’s castle, the Lords of the Union proclaim the forming of the Altirk Treaty to carry on Villar’s legacy. Lassic nominates Theo to lead the Treaty, but is unable to get the other Lords to agree, as Theo’s current list of military accomplishments falls short of their expectations for their leader.

In order to distinguish himself as being fit to lead the Altirk Treaty, Theo and the others head to Sistina. To save the citizens of Sistina from the Rossini family's oppression, they visit the towns of the domain, urging them to revolt, but the Rossinis' reign of terror is too deep-seated, and no one is willing to rise up.

As the uprising escalates under Theo, assuming the name of the hero, Cornaro, Phederico begins to feel threatened. Giving his eldest son, Dorni, five thousand troops, he orders him to subjugate Theo and quash the rebellion. And behind the scenes, the Black Witch, Jana, has a secret plot up her sleeve.

Theo has taken care of business in Sistina, with a new ally in tow. Meanwhile, Milza has been firming his grasp over Altirk, going so far as to successfully eradicate any rebellious acts. As Theo seizes back the Forest of Eternal Darkness, a battle between Theo and Milza become inevitable.

The battle continues in the Forest, as Theo tries to lure Milza's army deep into the Forest. However, not wanting to fall in his trap, Milza and his mage devise plans to draw Theo out. Meanwhile, as the Starcks and Nords close in on Haman, Lady Eudokia and her mage make a difficult decision.

As the Treaty armies gather around Castle Unicorn, Milza becomes very impatient. He tells his mage that even if Waldlind reinforcements show up, this would only endanger Lady Marrine. However, his mage tries to convince him otherwise that her presence will turn the tide. Will Milza listen to his mage?

As the Altirk Treaty moves foward, it declares independence from the Union. The Treaty vows to broker peace with the Alliance and Union by becoming a third force, and carrying out Villar's wish.

With the Union now mobilizing in full force, it succeeds in getting revenge for the Le Couleurs. However, their next vicious opponent awaiting for them on the seas is Sea King Erik. Will the Union prevail, or get crushed by the Nord's fighting prowess?

After a stalemate between the Union, Alliance, and Treaty forces, Theo calls for a summit. Here he hears from Marrine about the moves of the Mage Academy and what caused the Great Hall Tragedy. Marrine is stubborn at first because she does not want Alexis to go to war, and this also meaning the recreation of the Grancrest that caused the Tragedy; but when Alexis proposed to her despite her purity gone, she agrees to become his queen, therefore uniting all three forces. Theo, Marrine, Alexis, and Siluca agreed on certain terms, with Theo being the new emperor. Theo then asks Siluca to tell to the whole world what transpired during that time...but at the risk of the Mage Academy knowing it.

Just when things were settling down, Siluca receives a message that was sent out to all the other Mages. Apparently, all the Lord-supporting Mages are being slaughtered in the night by a mysterious secret agency.

After the Mage Academy declares war, the Pope brands Theo as a heretic, and declares a Holy War against the Imperial Army. Now, innocent followers of the Order block Theo's path to Eramu.

The Imperial Army finally reach the gates of Eramu. However, with the Mage Academy determined to stop them, they send out a dangerous enemy to meet them at the gate.

The Vampire King enters the stage. As the Mage Academy leader stands watch over Pandora and the entire Age of Chaos, will Theo succeed and bring the Age of Cosmos?