I couldn't stand the second Imprisoned battle. Mainly for that fact that if I fell behind, I couldn't get past his feet. He reached the temple once, and it was the only time through the whole game that it told me "Game Over". Third isn't so bad. You only have to deal with his feet once. And at that, I used the bow and arrow to take out one foot (I had that thing maxed out before I even took out Tentalus.) so that the other one was easier. With the Sacred Bow, 1 fully charged shot takes out a toe. And then just shooting him as Groose twice? That's simple. Easiest Imprisoned fight IMO. But I digress. The 2nd one was terrible. Especially when he slides like a penguin.
P.S. I noticed you placed Levias and Bilocyte on the list as separate bosses. The two are one of the same. The whole thing is known as the Bilocyte battle.