Ether and Abyss

Prologue

"Thine gates be guard
By Aegis dark and deathless
And quell thou charge, relentless, hard
Lest the Chaos sweep to the plane of man."
-Marituvud's Prophecy

Slicing free the beast's arm, Seif spun and slashed with the greatsword, burying the edge into it's chest. The thing roared, dropping a crude, jet black excuse for a club onto the aegean earth, and Seif rolled, clanking in his armor as his tawny cloak fluttered at his collar, not pushed by the eerie gusts of the Abyssal Plain, but instead by the shielded aura around Seif. Using his side blade, an ash colored gladius that was too small to be used as a real blade, the Aegis slammed the small sword into the back of the beast's knee, and as it buckled, jumped up onto its back, leaping into the air with inhuman strength and slamming the greatsword hilt deep into its shoulder, pulling it out with practiced ease and throwing it into the sheath on his back, jumping to the earth and rolling as the beast disintegrated. He rose stiffly and picked up the gladius, slamming that into his belt sheath as well. With that, he strode back to the howling gate of darkness, picking up his discarded long shield that he'd dropped upon the initial arrival of the behemoth. It was of a bash-and-parry variety, so that he equipped it by sliding it onto his forearm and bending his arm in a 90 degree angle to hold it up like a normal shield. Seif struggled to remember the name of the shield; like his greatsword of which had been made in an age long passed by, in a place long since closed. Light flickered ahead of Seif, and he stretched once more as he came to the Abyss Gate, taking a seat against the stone ring that marked it. One could think, by its name, that the gate was one like every other gate: a door to be entered and exited. The Abyss Gate was different. Shaped in a circle, the gate was a stone ring etched with ancient, inscrutable runes that pulsed like a heart, and in the center was the Gate itself. Swirling black matter and the occasional crackle of lightning made up the gate, and it seemed to orbit the center, which was like any other whirlpool, except Seif knew that, should he try to reach in close and have a look at it, he too would get sucked in, becoming oblivion, fueling the Abyss.
Humans knew this place under different names, though it all remained the same, and it seemed as though just speaking the word Abyss made every prophet and priest pale like they'd seen a ghost. With good reason too. Only the dead knew what the true Abyss looked like, and scholars called this place of the Abyss "hell" and "evil." Seif knew that wasn't quite true. Undoubtedly, the Abyss was, to some extent, evil, but Seif had come to learn that it was just doing its "job," so to speak. The Abyss destroyed. End of story.
Now, what truly made it evil, and why people feared it, was because the Abyss always spewed chaos. Faith in their "gods" made them feel safe, and they lived lives of order, and not in fear. But it always came down to the same matchup: Seif, the undying bulwark, and Chaos, the unyielding, invincible, force of power, without equal, and constantly attempting to push through to the gate. Constantly trying to get to humans. It was Hell. And it was pushing against a wall. A strong wall, but still, a breakable wall. Seif.
And should that wall break...
Well, then it would be our end.