A/N: Hi all! This is my first fanfic, and I hope it does justice to the perfect and predestined crossing of Three Houses and Avatar. (Or as Odin would put it, such are the Whims of Fate!). In a Fodlan where the Four Elements play a central role in life and war, will the heirs to the Three Houses lead their nations toward balance and enlightenment...or plunge each other and the world inevitably into the inferno?

Now it's time for the obligatory intro (in Hilda's voice)!

Water. Earth. Fire. Air.

Long ago, the three nations and the church lived together in harmony. Then, everything changed when Emperor Edelgard attacked. Only the Avatar, master of all 4 elements, could stop her, but when his students needed him most, he vanished. Fortunately, Claude and I were able to rescue him, and although he still remembers our lovely faces, he has some serious catching up to do before he's ready to save anyone. But I believe... Our Professor can save the world!

Prologue: Air

Seteth surveyed the distant grounds below. It was still hours before dawn, and the light of the fading stars afforded only partial vision.

They found him, Rhea had said. It could only mean one thing. The child of prophecy had awakened to Sothis.

He had only managed to summon two elite pegasus knights to shadow him on this mission - anyone else would have slowed him down. Their graceful movements contrasted with the powerful and heavy wingbeats of Seteth's mighty dragon, Roku. The spiritual auras of the pegasi shielded their riders from the storm. No such luck for Seteth, who unfortunately had to tough it out through Roku's elemental weakness.

It had been the first time he had seen Rhea so distraught. As with his brethren, the power of Air granted Seteth limited ability to foresee the future, but true prophetic vision required a gift and training in detachment that, to his knowledge, only the current Archbishop possessed. Yet he was sensing that Rhea was not completely dispassionate in this. Could it be that she was hoping for the return of her …

He fought to pick up speed, knowing every moment could mean the difference between slaying the assassin and finding an entire village obliterated. They flew on over Gronder Fields, the Valley of Torment, towards Fodlan's Locket.

No, thought Seteth, it would be wrong to think the Archbishop so naive. The latest reincarnation of Sothis would not inherit any of her memories or personality. In fact, it was unclear whether he would inherit any of her traits at all. It was not uncommon for the Avatar to lead a perfectly normal life, in the absence of any particular guidance or extraordinary interventions.

The first hints of dawn could be seen on the eastern horizon now. In just a few moments...

Seteth spotted his target heading north along the Airmid River towards a village at the edge of Goneril territory. The dark rider was moving tremendously fast, with two other horsemen in tow. Seteth bid Roku and the other knights to descend as they slowly gained on the riders.

"Archers!"

The yell came from behind just as their flight path was intersected by a flurry of arrows from the two riders in back. Roku's tough scales shielded him from damage, but one easily broke the pegasus's wards and pretty soon she and her rider were tumbling out of the sky towards the river below.

Blast! Arrows forged with Agarthium likely meant they were dealing with one of the Elites. Without any hesitation, he and Roku dove down towards the ground like a meteor. Fire erupted from Roku's jaws, lighting the riverbank below in a blaze which quickly engulfed the bow knights. Though temporarily blinded by the light, he could hear panicked screams as the riders were incinerated.

But by then the leader had escaped towards the village, easily slaying the men on watch and sweeping aside the gate with a powerful blast of earth. Seteth and his remaining adjutant flew over the city, frantically sifting through the chaos.

They located their target on the riverbank just outside an old cottage that Seteth recognized as one of the orphanages run by the Church. Not daring to use Roku's flames here, Seteth charged the rider from the sky, aware that dragon talons could be just as deadly as Fire. But before he got close, the earth below trembled and a dozen rocks launched themselves at the fliers. One shot down the remaining pegasus knight and Seteth heard the breaking of vitals as they crashed into an inn. Meanwhile, his target escaped into a narrow alley.

Seteth leaped off Roku with spear and shield in hand, forced to confront his enemy on foot. As he approached, he got a better picture of his foe. The predawn light was just enough to reveal the obsidian black armor and helmet, along with the kind of terrifying potential that often emanated from the most gifted of dark mages. In his hands he carried a glaive-lance encrusted with a glowing red jewel like an eye, which Seteth instantly recognized as the lost Hero's Relic Areadbhar.

"You're late, Cichol! The King of Liberation will free this world from your shackles!"

Seteth's eyes narrowed. "Lord Blaidydd of the Ten Elites. You are mistaken. I will be the one to finish you, and your King will remain locked away in the shadows of history where he belongs."

"We will see." The dark knight's terse reply made it clear that he was not here to have teatime with Seteth. Unfortunate, thought Seteth, not only because he could have used the caffeine, but because dawn was still minutes away, and now he would have to mark time though battle.

His enemy dismounted and, with a single sweep of his lance, produced a violent shockwave in the ground. Using the power of Air, Seteth pressed his body to twice its normal speed. Sensing the subtle movements of the ground beneath, he leaped up just as a fissure opened underneath him. He counterattacked with two sharp bursts of wind; one sliced cleanly through the roof of a nearby house and collapsed it. But the knight raised a stone shield that easily blocked the attack. A split second later he felt a vicious impact as that same shield smashed into him midair.

The impact knocked him all the way back into the nearby stream. Dazed and injured, he prayed in the water for a moment and felt the spirit of his daughter renew his energy and heal his wounds. With Assal and Ochain in hand, Seteth quickly closed the distance in order to fight the knight at close range. The enemy was fast, however. He dodged the first two of Seteth's well-aimed strikes before counterattacking with a powerful sweep from his lance, which Seteth barely caught with his shield. Two more strikes with Assal, and this time one of them connected with the knight's armor, leaving a magic-encrusted mark.

His enemy changed tactics and the ground beneath Seteth softened, inhibiting his movements as though he were fighting on quicksand. Another blow from Areadbhar came, but this time Seteth couldn't maintain his footing and had his shield knocked aside. He tried to withdraw but the ground sealed his movements like wet mortar. The enemy saw his chance and charged in with a lethal blow.

He was just a few seconds too late.

As the first rays of the sun peeked out over the horizon, Seteth drew in a mighty breath, the air around him instantly crackling to life as though a million tiny currents were passing through it, fusing particles together into pure energy. Directing the blaze downward, he propelled himself up from the ground to escape the sand tomb, then, focusing the energy further, aimed an immense fire blast at the astonished knight in black. The earth he raised to shield himself was no use, the fire permeating through the cracks in the earth and demolishing the shield as though it were dirt clinging to an old tombstone.

Seteth approached the knight laying defeated on the ground and readied his spear to take out his throat. The old warrior gave one last gasp as his moment of death approached. "Long live Nemesis!"

Then the spear pierced his neck and the dark knight Blaiddyd fell silent as a grave.

With flames quickly dying down at his behest, Seteth opened the door to the old cottage and, venturing upstairs, found the baby, pulse beating without a heartbeat and hair the color of Rhea's.

After briefly examining the wreckage of the battle - and leaving a generous donation in the coffer for necessary repairs - Seteth returned to Roku with the child and the lost Hero's Relic. The three made their way up to the sky and back towards the Monastery, just as the edge of dawn lifted into a new day.