Good concept :]
It's cool how you use the panning in the percussion.
I'm not familiar with making music in this genre, but I recommend to play around with the velocity of the drums a little, so it gets a more natural sound.
Secondly, you should put in some strings, that gives the song a bit more body. And perhaps some higher notes in the strings, not too much, but right now it sounds a bit low frequency.
Also, the bell sounds at 1:15 are just cut off. You could find some church bells or tubular bells, at least so you have a full sound, that isn't cut off like that. You could also give it some reverb, to stretch the sound a bit.
The concept is good, just needs somethink that makes it sound more real and natural. There is a lot of 'smashing around' on the toms, try to make it sound more like an epic rhythmic section.
You could listen to some other songs as an example. One song that I could recommend you is 'Best of Times', a soundtrack for the World of Goo game. From around the middle of the song until the end, there are some epic stormdrums.
Now I'm not telling you to make it absolutely sound like that, but it could work as a nice example. Try messing around with an Equalizer, just to bring various frequencies up or down in the sound of your drums. Some slight reverb would also work fine.
I hope it helped you a bit with this long-ass review :P
Keep it up! :D