I didn't mind him the first time, but The Imprisoned became a vexation the second I realized I had to stop him from reaching the same goal two more times, on the same battlegrounds. To be perfectly honest, he could be the worst boss I've ever gone up against.
The conceptional design of this boss was rather humorous and preposterous. I mean, if you take a step back it looks like a brown pineapple with droopy arms, dinosaur legs, a sweeping tale, a gaping maw of pearly whites, and eventually that dark halo thing it uses as "wings". It's not very frightening in thought. But The Imprisoned was a slow rampaging monster with only a few soft spots: its toes. As much as the concept design seems laughable to me, this one really takes the cake. It's like I have to hack at his feet to relieve them of toejam, and that cleanliness causes him to faint.
The only fun moments of the fight were being launched from the Groosenator to his head, or better yet setting up aerial strikes with the bombs to bring him down. Other than that I hated having to go around him. That incensed my aversion to this boss and begrudge the scenario even more that it's mandatory to fight those three times. Also, three times is bad enough, but six in all if you count the Lightning Boss Round is worse by far.