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A/N: Welcome, one and all, to Tales of the 51st Millennium! Despite it's title, this short story collection began as a series of omakes for the main Code Geass 50k story, but due to the sheer number of omakes planned, they are now split off into their own section. Despite its title, the stories here will cover not just the 51st Millennium but everything in between. The Great War, the Necrotic Wars, you name it. There will be serious stories, and a few silly ones mixed in here and there. How to tell the two apart? The serious ones (or at least the ones that could've happened in the main universe) will have a brief, italicized paragraph explaining the context in the wider galaxy.

The Battle of Deneb

Officially known to the Imperium as Alpha Cygni, the Hive World of Deneb is located deep within the Ultima Segmentum. The system once played host to enormous Mechanicum mining stations plundering rich veins of heavy metals and stellar hydrogen to fuel the Imperium's ravenous war machines. Those days have long past, and Deneb's only notable resource now is its people. While overlooked by Abaddon's forces, Deneb found itself in the path of a Necron harvest fleet during the closing years of M50. The battle fought between Necron legionaries and the 5th OPAW on the Hive World's surface resulted in one of the Black Knights' first clear victories of the Third Necrotic War, bringing notability to an otherwise-unremarkable campaign.

Lances of red and green crossed the battlefield as the 5th OPAW continued its advance up the hive. Of all the enemies that the Black Knights had ever faced, the Necrons were definitely the toughest. The 5th OPAW had lost many good men and women to the enemy Gauss weapons, which bored through their battle suits alarmingly quickly. Their hadron carbines blew holes in the Necron formations, reducing Warriors into twisted scrap metal, but the enemy just kept on coming.

When a sudden meteor shower appeared in the sky, the morale of the 5th OPAW threatened to break. The Black Knights orbital support consisted of the destroyer Avalon and a squadron of frigates, up against a Necron fleet of roughly similar size. The last report was not good, and if debris was raining down the atmosphere…

"We got word from the Avalon! Confirmed kill on Necron Harvest Ship!"

A cheer rose throughout the 5th OPAW, as the Necron vessel broke up in the atmosphere. The Scythe-class Harvest Ship was a tough ship to hit, and even harder to bring down. The Avalon had used its powerful forward-mounted hadron cannons on it, and, even then, it took several FLEIJA volleys to bring the monster down. Despite the difficult battle, the news did wonders for the ground forces, which began advancing through the rapidly-thinning ranks of the Necrons, now cut off from reinforcements.

The 5th OPAW rushed down the ranks of the Necron Warrior squad, rapidly closing the distance before sending a wall of hadron fire at them. Several were blown off their feet, and the green flashes of Necrons phasing out were gratifyingly common. When the battle became close-in, it was a small miracle that the members of the 5th OPAW were not hitting each other with their weapons. Many had switched to their hadron swords, taking advantage of the clumsiness of the Necron Warriors in melee combat.

"Necron Lord! Shoot it! Shoot it!"

The members of the 5th OPAW not involved in the melee turned their carbines towards the towering Necron Lord, sending a storm of hadron bolts into the automaton, to little avail. They pockmarked the monstrosity's armor, which just flowed back together. The thing lowered its staff, vaporizing one of the OPAW members with a stream of lightning. Participants in the nearby melee, now clearly an OPAW victory, were beginning to add their own firepower towards bringing down the Necron Lord.

Slowly, the wounds taken by the Necron Lord began to add up, and the thing slumped, seemingly using its staff as a cane. A few more shots caused it to finally fall over, before phasing out in a flash of green.

"Hey, has anyone seen Johann?"

The members of the 5th OPAW quickly sounded off, and, surely enough, Corporal Johann Nathan was missing. The members of the 3rd Squad began to broadcast on the squad channel, in hopes of locating the missing Corporal, but were saved a lot of trouble when the said Corporal's voice broke into the channel.

"Aiiiiiieeee! They're everywhere! Everywhere!"

"Corporal! Calm down! Just keep talking and we'll trace your position!"

The Corporal's panicked screams were heard over the chattering of a hadron carbine, doubtlessly his own, and the ripping sound of Gauss flayers.

They found him an hour later, huddled in a corner and muttering "Cold. So cold." Any attempts to find out what had happened were only met with silence.

Battle of Deneb, After Action Report Supplementary: On the topic of Corporal Johann Nathan, 3rd Squad, 5th OPAW, it was determined upon review of his helmet camera footage that he had taken a wrong turn during a firefight, and was separated from his unit. While attempting to rejoin his unit, he encountered a Necron Pariah squad attempting to flank the main body of the 5th OPAW. In taking them down, the Corporal suffered severe psychological strain from exposure to their psychic-blotting aura, eventually going into a state of severe shock. He currently remains in the medical wing.