First to comment/like. Good story, good job. It might not be good because I have low expectations but to me it was good!

Hmm, interesting.

but doing nothing to conceal the pair of long yellow-orange horns

Uuuuuum
images5.fanpop.com/image/photos/30200000/Trolls-homestuck-trolls-30218076-1024-710.png

In all seriousness though this is a good start. The atmosphere was built good with Rumble exploring and the backstory of the mansion, and you left on a good dramatic note. You do description very well also, but there are areas where I feel there could be a little more.

in one strange and somehow unnatural motion, seemed to define gravity itself in order to push away from the floor.

Does this mean he floated up to his hooves black mage style, or that he did some super equine acrobatics like a Devil May Cry character?

Also,

seemed to define gravity

Yeah, you really need a proof reader dude. Don't know where you'll ever find one though. *Hint, hint, nudge, nudge*

5575630 Honestly, I wasn't thinking of Homestuck when I wrote this. And thanks for pointing out the errors.