It's a Nightmare Moon battle theme.
I picked the best picture I could find (that hasn't been used by someone else).
Credit for artwork goes to nikohl.
I really tried on this one, but there are still some parts that don't quite sound right.
Let's just use "emotion" as a cover-up for those, hm?
Yes, it's a remake of Nightmare -- if you listen, the second half has the lower string progression directly from that (transposed, of course).
Anyways, hope you all enjoy.
It was a Nightmare to make =P