F yea Atma Weapon!!
I've been meaning to get to this song for quite a while. It's one of my favorite FFVI songs alongside Dancing Mad and Decisive Battle. I've always been intrigued by how unique the synth part sounds. It's actually 3 or 4 different instruments playing the same line in different octaves and one playing 5ths.
As awesome as the original is, it feels rather short, so I was looking for another song to supplement with it and landed on The Unforgiven, the song that plays during a lot of 'now im pissed' and 'hurry the hell up' moments during FFVI. I had to slow it down a tiny bit to match Fierce Battle's tempo, but the two go really well together.
I'm not really sure why I like the word 'Atma' so much, I guess when I first played the game back around the time it came out it just reminded me of this awesome song, and how fierce (battle!) the Atma Weapon is. Just look at those muscles.
...and of course, the awesome blue sword.