From what I've seen it's also one of the most gorgeous, but then again, I like stars and floating planets. Algalon himself is an entity composed of stars, a spectral being who is not uncompassionate to the heroes who have come to kill him. He just has a job to do. A job which could see our world being put in serious - even cataclysmic jepoardy.
Needless to say, from here on in, there be SPOILERS about the actual boss fight so read on at your own peril!