Ruglis had long since stopped feeling pain, he had long since forgotten the diseases that ravaged his body, the horrible mutations that had burst through his mouldy green power armour. Large bone growths forced through tears in his ceramite pauldrons, in the armour of his knees and out of his skull and through the cracks in his helmet, just above a triplet of glowing blue optics.

The plague marine lay upon a featureless landscape as the horrors of the warp moved about him. Glancing over to his right he saw a Skulltaker, the deep red daemon was dressed in a robe of skulls and covered in symbols of the Blood God, in its right hand was a glowing hot blade that burned with the same hatred as its master, in its other hand was a blackened skull that was on fire and somehow wasn't burning the daemon's hand. Ruglis tensed visibly, his hand grabbing at the handle of his scythe, the weapon had a slight bent wooden handle, the blade was stained red from the blood off countless enemies he had slain.

"Ruglis, son of Mortarion"came a booming voice"I have a proposition for you"

Ruglis' eyes widened in shock though he didn't dare move in case he alerted the daemons crowding around him.

"I am the God emperor of Mankind"the voice came again"I need you to do a job for me"

What? Ruglis thought, he attempted to speak but instead came a horrible gurgling, wheezing noise from his ruined lungs.
"I see Nurgle's rot has taken its toll upon you"The emperor mused"But no matter, soon you will have your voice back, I am sending you to a world that needs your protection, in a new form and body, I am giving you at a chance of redemption, to be cured of the diseases that rampage inside your body, to be free of your suffering"

Ruglis wheezed again managing the words "What..do.. you.. mean?" A couple daemons hesitated for a moment before continuing.
"I will send you to a world that requires protection against the evils that plague it"The emperor chuckled at his own pun"Anyway if you do accept my offer, you should know many things I cannot heal, such as the bone growths and some of your mutations, so"He paused for a couple of moments"So do you accept?"
Ruglis nodded, making another dull wheezing noise, he would do anything to be away from this place and away from Nurgle's clutches.
"Good"Suddenly there was a bright purple flash as the air around him warped and spun and the loud voice of the emperor boomed"Goodbye Ruglis, I do hope we see each other again, though I may not recognise you

In Equestria:

Nothing told anyone of the great magical discharge that tore the fabric of reality apart. The amount of magic crashed across the land like a wave, disturbing many from their sleep as they woke bleary eyed and confused. Then the screaming started, the cries and sobs of a thousand souls suffering in a place of pure insanity, those who hadn't woken up had now. Dragons, griffons, ponies, all creatures of the world instinctively turned towards the Everfree forest. The 3 princesses weren't pulled from their slumber, in their dreams they saw a giant stallion, bigger than Celestia, dressed in dark green armour. In one hoof he held a blood stained scythe, the helmet's three port holes glowed dully. A pair of large shrivelled wings were spread out behind him, large spike growths of bone protruded out the top of his skull, back of the knees, shoulders and spine, stallion kept making low coughing noises as if he was struggling to breathe and was shaking in what seemed every breath. They attempted to help him, to comfort him but the stallion just screamed, roaring in rage and agony, raising the scythe towards them before everything went black.