Well, this is going to be my first multi-chapter fic, and second overall fic, and I hope I do well. I saw this as a prompt of Homestuck characters being in Slender or playing Slender, as I thought that would be interesting. I'll stop rambling now, enjoy. (I hope.)
Karkat ceased his running, heart pounding desperately from the exertion. He fell to the ground, looking all around him before backing up against a nearby tree. His breath was coming out as uneven gasps, in a way he was almost certain would give him a heart attack. Curling into a ball, he tried to calm himself, quietly singing bits of nursery rhymes in the strained attempt to stay sane.
He reached for his flashlight, hugging the object rather close to his frantic chest. It was coming for him, and he knew it. He knew he had been down for too long, and that he had to keep going. Inside however, he knew there was no way he would make it. He swallowed nervously before standing again, adjusting his small backpack so it wouldn't bother him as much or slip. He looked around again, and to his surprise, still nothing. Oh, but not for long. Never long enough. Karkat felt a sudden chill go through him, piercing through his heart, and stunning him like a deer in headlights. Then the static noise. He was no longer alone. It had found him.
Karkat suppressed the urge to scream and bolted, trying to make his way in the eerie darkness of the forest. The batteries in his flashlight seemed as loud as thunder claps, his feet pounding against the ground like that of an elephant, both almost silent compared to the ringing in his ears. He didn't dare look back, he could only look to where he was running. Yet the static didn't cease this time. It only sounded closer, as though it was coming for him. This was it. This was the end.
Karkat gave into the burning fear and managed to stop and turn around, seeing nothing but the trees and shrubs he'd just passed. He almost felt a moment of relief. But the static had remained. He summoned all his courage to turn around again- and there it was. No more than fifteen feet away.
Karkat stopped dead, his heart nearly exploding from stress in that moment of fright. All he could do in the final moments was drop to his knees. It was over.