Complex sentence: Deep Blue is the leader of the aliens trying to take over Tokyo, his identity is shrouded in mystery until volume 6 of the manga, in which it is revealed that, like the Blue Knight, he is part of Masaya Aoyama.
Split into simpler sentences: Deep Blue is the leader of the aliens trying to take over Tokyo. His identity is shrouded in mystery until volume 6 of the manga, in which it is revealed that, like the Blue Knight, he is part of Masaya Aoyama.