I just hated The Imprisoned. It was an annoying and hard battle, epsecially the third battle. The Imprisoned was a boss with nice features and all that, but wasn't fun to beat at all. There were a lot of better battles with better bosses. The Imprisoned was my second most hated of all Skyward Sword bosses.
The one boss I hated more than ever, even more than The Imprisoned, was Demise. He was REALLY hard, and took me loads trys to finally beat. The battle area was good though. It was fit for a boss like him. I'm sure many ZD members agree with me, Demise is HARD. Though I really liked the second part, Demise beats me almost every time. Thats why I hate him. At least I can beat The Imprisoned a lot more, Demise is just plain hard to beat. The lighting in the area doesn't make it any easier. The music was blah too. Thats about it.
P.S Demise wears a skirt.