Ruglis felt pain for the first time in three thousand years, a horrible burning sensation that clawed his fur. Wait, fur? He sat upwards, though he could not see it under his power armour he felt fur or hair underneath. His armour had changed, the arms, or legs had flat ends like an equine's feet. Slowly, painfully getting to this hooves, he looked at his flank. Covered in dirty green metal, aside from the withered wings sticking out the ceramite, it was a definite horse's body, large bony spikes protruding from his spine, the armour cracked, more were growing out his shoulders and knees. Ruglis could feel that the armour was still fused to him in several places, blood pooled out those places, like his shins, back and neck. Crossing his eyes, he spotted a long snout under the helmet. Fumbling with his helmet due to his flat hooves, he threw it a little way away as gave a long, rasping, wheezing gasp as his ruined lungs attempted to inhale oxygen. Coughing loudly, he picked up his helmet to have a look at it, it still had its three dimly glowing optics, several ram like horns were attached to the top pointing upwards, there was still a splintered hole, the ceramic feathering towards him, feeling the top of his head, he found a long curved horn like growth. Flicking his ears to the sound of running water, he shambled over to peer into the shallow liquid. A horse's face stared back, it had a matted black mane tied in messy dreadlocks, Ruglis' fur matched his power armour with terrifying blood red eyes set into his face. Ruglis struggled to replace the helmet on his head. A scythe was embedded into the grassy floor a few paces away, his scythe, the weapon that had been with him almost all his life. Pulling it from the ground, he examined the blade and the handle, scrutinising them for any blemishes. Wheezing, he raised the scythe, the handle somehow sticking to his hoof, the plague marine shouted as loud as he possibly could
"PRAISE THE EMPEROR!"

The forest was silent as the grave as the plague marine strode through it, he could see the morning sun breaching the treeline. Coughing again he continued towards the direction of the sun, as if he wanted to chase its beauty. He continued for hours unsure what to do, then he heard the shreik.

Canterlot: A couple hours later:

Celestia and Luna sat together at breakfast early in the morning, the sun princess ate a small piece of cake, while Luna shakily moved to drink out of a small teacup. "I'll assume you saw it aswell?" Celestia asked her younger sister, who nodded.
"I had my work cut out for me last knight as many suffer from the same horrible visions"Luna replied" I want to find this mysterious stallion and demand why he disturbs the sleep of so many"
"I must inform Twilight of this, for her to look out for anything odd that leaves the Everfree forest" Celestia added, suddenly there was a small pop and a scroll landed before them. "Speak of the devil "Luna chuckled as Celestia opened the letter and began to read, her eyes widening. Eventually she put it down and stood up "Quickly we must make haste to Ponyville" Celestia said" It seemed Twilight has beaten us to it"