So, my first...masterpiece... Is out of the way.
Now for my second.
As you may know, there were originally 20 Primarchs, before Chaos sent them throughout the galaxy. All twenty were found, but two were expunged from all records....purged.
Several typical marks of a mutant corrupted by Chaos are hooves, horns, and fur. Other, less common marks are wings. All of the Primarchs rise to power and prominence in the worls they landed upon.
Now the story of the Eleventh and Second Primarchs can be told.
The First Mutant.
Catchy title, don't you think?
Basic summary is as follows: the eleventh and second primarchs are Celestia and Luna. Story starts in mens rea, with the Emperor looking down onto Equestria, where two of the lost Primarchs are located. The Emperor watches the scanners, and gets angry when the scanners don't detect any human life forms.
We then flash back to the start, with the capture of the Primarchs by Chaos. Emperor bursts in after in a fury, yelling at his scientists that the Primarchs must be found. Almost does a Darth Vader on one of them.
Flash back to action, and Emperor prepares to lead boarding party down there. Reflects on other locations of the Primarchs. Last scene from his perspective.
Switch to Princess Celestia, two days earlier. Summer sun celebration, first after defeat of Discord. She reflects on her history, and especially her mysterious origin. Memories turn to Discord, The First Mutant. Flash back to the days of Discord being deposed. Mentions purity somewhere.
She is brought back to the present by Luna bursting in. Apparently, some vast magic has been detected (heralding the arrival of the Imperial ships). She composes a letter to Twilight Sparkle, to see if her friends have noticed anything strange.
She gets a response, basically saying not much. This Is A Lie. Celestia goes to summer sun celebration, yada yada yada. Brief snippets of life before arrival of Imperial ships. Celestia summons elements of harmony and Luna, to prepare for anything threatening to harm Equestrian way of life.
Emperor is at this stage far from the human reaches, and doesn't want to conquer anything, just wants the Primarchs.
Swap to Twilight, and some strange things are happening. Need Ideas. Possibly Discord Level, But Not Definitely. She gets the letter from Princess Celestia, but worries about what her mentor will think when she hears Twilight can't deal with the problems on her own. Little does she know that They Are Caused By Imminent Arrival Of Imperial Ships. She tries desperately to fix them, but to no avail, and she is summoned to Celestia too quickly to fix them.
Should I Do Luna As Well? Or Is It Getting Boring At This Point?
Anyway, the main cast up to speed on events, Twilight and others stand before Emperor, don't have idea for what happens now.