Or: Epic Endgames are Epic
It shouldn't have been possible, the way he moved.

Excuse me, where are my manners? As much as I'd dearly love to prattle on about how imposing and incomprehensible my name is supposed to be, greater devils get that privilege; an imp such as myself must make do with a lesser name, such as 'Brintari', which is, incidentally, the name you may choose to know me by. I was on special assignment into one of the upper layers of the Abyss - a suicide mission, really, with the purpose of gathering information from the Eighty-Third layer - when I noticed a massive portal opened to one of the planets on the Prime Material Plane. I, of course, went to investigate immediately and found an army of the Tanar'ri pushing each other towards the portal, blood flying everywhere in their eagerness to leave their home plane.

Ah, demons. Their stupidity makes me feel warm inside.

Which brings me to what I was talking about initially, for a group of six mortals stood just on the other side of the portal and were, astoundingly, holding the line against the demonic hordes. One of them, a sorcerer or arcanist or whatever mortals call them, chanted and unleashed a wave of crashing thunder that deafened the Tanar'ri ranks, driving them back from the sheer sonic force of it, and their priest invoked the name of some wretched god of light and turned the front ranks of the demons into ash. They barely even got time to scream.

"We cannot hold!" one of them shouted, even as she blasted a storm of fragmenting arrows into her enemies. "We need reinforcements!"

"That'd be a great plan if someone hadn't used his last scroll to get us here!" another one shouted, a half-elven boy wearing dozens upon dozens of daggers in place of armor. He and a tall woman holding a claymore stood in front of the group, ready and wary, and a collective groan went up directed at the magician.

The priest was about to say something when the boy - or was he a man? There's so much difficulty telling, with half breeds - dove into the portal, bringing his blades up in an impossibly fast scything motion that cut down a pair of demons at the waist.

"Francis!" the woman with the claymore shouted desperately - sweet grief! - as she started forward, but the half-elf waved a hand at her impatiently and shouted back, "Get reinforcements! I'll hold 'em here!"

"Gods damn it Francis, you aren't invincible like you think you are!" she protested, tears in her eyes, but the sorcerer grabbed her shoulder and gave her an intense look. As one, the group turned and ran, dashing away as fast as their feet could carry them. I stayed to watch the death of the boy.

Except...except there's no way he should have moved that fast.

In the brief time I'd looked away, he'd hacked down eight more demons, slicing through beings that must have been a century or more older than him at the youngest like they were feathers. He moved like a hurricane, like a god, a phantom of flickering steel and that white, white smile, always slashing and dancing away before the first flecks of blood could mar his clothes. Demons would lunge for the doorway only to find him before them, twin blades ripping into arteries and severing limbs with the neat, surgical efficiency of a butcher, and all the while he laughed merrily, like it was a game.

The seconds dragged on into minutes. The minutes turned into half an hour. I lost count of the number of corpses he piled before that gate, but he was slowing down, and reinforcements were coming to the aid of the Abyss.

A demonic sorceress, a succubus of some power, flew in and opened up not with words, but with a black ray of death that the half-elf deflected with his blades. He replied by hurling a pair of longswords at her, the blades lengthening from their dagger-sheaths as he threw them, which sliced her wings off and sent her plummeting to the earth. Her counter-attack was a wave of fire that scorched her assailant, making Francis scream in agony.

"There is no victory for you here, mortal!" the sorceress screamed triumphantly as he picked himself up. The rest of the fiends edged away from him, for as he stood a radiance began to emanate from his flesh, waves of glory crashing from his form to blast them back.

"If there can be no victory," he whispered, clutching a dozen bleeding wounds, "then I will fight forever!"

There was an explosion of light, and I blacked out.

* * *

I came to some hours later, and standing before me was a goddess; tall and red-haired, fair of face and holding a glaive in her hand. She wore no armor, instead clothed in only a tabard that shifted symbols so rapidly that I could not keep track of it. I hit my knees and trembled, begging for my life.

"Brintari," she said softly, and I looked up in terror, "be not afraid. I send you with a message that your master should find pleasing. Tell him that my name is Trivalla, and that his actions have helped me come to be. Tell him that I am the goddess of courage and glory, and that I do not forget my debts. But tell him this as well: my champion has cast his lot with the Planes Above, and while he lives, so too must I. Abide in patine, Brintari. Your day will come, when you may know the glory and terror of those below you."

She turned and looked with a smile at the half-elf, fast asleep on a pile of demonic corpses high enough to build a mountain.

"I would be very grateful if you could return Francis to his lover," she asked of me, and I nodded quietly. I barely even noticed when she vanished, and went to do as she asked.

Master would be pleased indeed.