Oh, it was.
Which is probably why I'm voting for it as well.
Emerald was the only one to have an intimidating presence outside of the battle screen. Every other boss tends to just sit there in one place (like Omega in FFVIII), or just be a random encounter. Emerald wasn't. He was waiting, lurking, hunting... Always around the corner. Always ready to toast you. And, if you hit him accidentally, you were dead. When you first fight him, you'd be fighting, and be being beaten, but holding on, just trying to keep going before that time limit completed (even though you had no idea how long of a fight it was, because, let's face it, no one wastes time with Sense), and then... Aire Tam Storm.