Alright, here's a really short piece of work from me. It's based on an idea that I had flying around in my head for months now, but only now I had the muse to actually write it down.
There may be several grammatical errors in it, but then again I'm no native speaker as you might know, so please don't be too harsh with critique concerning that ;)
Anyway, here it goes: Enjoy :)
He smiled as his sword drew a thin line of blood across his face.
"I'll be right by your side, my lord."
Lucius remembered the very moment that was depicted on the giant canvas like it was happening just now, right before his eyes.
Almost a year before the Cleansing of Laeran, Fulgrim and a speartip of his chosen amongst the Emperor's Children had led the final assault against the alien-friends of the Castiani Clan aboard their flagship to deliver the lethal blow. The preceding battle in open space had been epic, and now it had come to the moment that would seal the fate of the rogues. The Phoenician's speartip had surged through the giant ship – a bizarre leviathan made of flesh and steel – like a tidal wave, blowing every last resistance to dust were pure power of Astartes had met xenos body fused with human weaponry.
In the heat of the battle, Lucius had been at Fulgrim's side when he and the Phoenixguard had forced their way through to the bridge of the vessel. When the warriors of the primarch's honour guard had met the giants of the Mor'ssal, the heavy armoured champions of the Castiani Clan's leader, Fulgrim had taken on the xenos overlord himself, in a duel worth remembering. The Phoenician fought with grace and perfection, while the alien commander, Jerd'Lab - a towering brute - had simply used a bulky club of metal. It reminded Lucius of a giant wrench, now that he saw it again. It had made his primarch sweat to overcome the xeno's defensive tactics, but after landing some well-aimed blows and a thought-out feint, his magnificient sword Fireblade had cut easily through the enemy's neck armour, slicing his head clean off his shoulders.
Lucius focussed on the painting again. There was his primarch Fulgrim, standing on top of the black-armoured figure, holding the head of the foe he had just slain high above his sons. The lighting was perfect on this one, the dead and pallid flesh of the alien a blemished contrast to the shining gold and pruple armour of the Phoenician. To his feet, the warriors of the Phoenixguard were ending the lives of their last opponents. Every one of them a hero on his own. Lord Commander Vespasian was there, and Lord Commander Eidolon was on his side. One day,...
The flow of memories was suddenly interrupted, when a voice rose behind him.
"I wonder if Ferrus has ever seen this...he might have learned his lesson before it was too late."
A hand was laid upon his shoulder. Lucius licked his lips, he had not heard anyone approaching.
At once, he spun around and had the tip of his combat knife right at the newcomer's throat. He relaxed as his thoughts of paintings and former glory vanished and were replaced by the flawless face of a well-known battle brother.
"You were daydreaming, captain? That seems not like you at all."
"Do not mock me, Apothecary. Why did you approach me like that?"
"I didn't. I addressed you twice, actually, but you showed no reaction. Forgive me."
Lucius grunted. He didn't like the Apothecary, but to the following, he was bound to obey.
"Come with me then, Captain, the Phoenician orders it. I have matters to discuss with you. Lord Commander Eidolon has already told you I would come, I assume?"
"He has indeed, in fact I was only here waiting for you. The Primarch has already returned from his conference with the Warmaster, and as it looks, we're about to leave this system pretty soon."
Fabius said nothing and simply turned to leave, and now it was Lucius to grimace at the Apothecary.
The Astartes headed for the giant lifter at the end of the great hall that was known as the Gallery of Swords. It would bring them down to the laboratories of the Apothecary, of that Lucius was sure. While he followed Fabius, he took a last look at the picture of his primarch's victory that he had marvelled only a few minutes before. Next to it was the beginning of a long row of portraits. Portraits of all the Lord Commanders the Emperor's Children had had since their birth as a Legiones Astartes: Vespasian, Eidolon, Acarion, Cyrius and many more, even great Azazel was there.
But there was something to them, something that Lucius couldn't place on the first glance. All of them were or had been noble warriors of great skill and artifice, of that there was no doubt, but he relished the feeling that he could, soon, rise above them all.
In passing, Lucius ran a fingertip over the gold leaf of the last frame in the row and smiled again.
The frame, to the painted Vespasian's right, was empty, but it was soon to be filled. The next portrait in this row was going to be his, and it would be magnificient.
Lucius was sure, through the grand array of marvellous colours, he would be granted to live forever in the minds of his brothers. And then it came to him, in the next fraction of a second, the captain of 13th Company made a silent promise to himself.
Even without them, he would live eternally.
I like it.
The only thing I would suggest, and I'm not sure how you would achieve it.
Would be to reflect Lucius' arrogance more, somehow.
He really thought he was superior to everyone else.
But I still think you did a nice job. I especially like how you mentioned his dislike for Fabius.