|“||Because I want to mate with you.||„|
Cerebrum is a shape-shifting villain who tempts people to become Daemonia in order to collect their souls.
Cerebrum has no set appearance or even gender, as it can modify its DNA structure to whatever it wants, thus allowing it to take any shape it wants. (Cerebrum takes advantage of this in The Moon's Light, The Sun's Shadow and playing with Luna Tsukuyomi's sympathies by changing into Akari Taiyou)
His usual appearance is that of a teenage boy with light blue hair that obscures one eye. His most defining characteristic is his bright blue eyes - this feature carries into all of his forms, even when he changes into Akari Taiyou during Episode 9, though this is not prominent until later in the episode.
When in his usual form, Cerebrum wears a black cloak with a hood and blue patterns.
Cerebrum is cold and cunning, sly and sneaky. He is determined to get what he wants and as the reverse sun tarot even draws the shadows closer to him. He is shown to do whatever it takes to get the results he wants such as manipulating Luna, sending Ginka's opposite against her and turning Luna on Seira, all to manage to mate with Akari.
Cerebrum has also shown he is unafraid to have fun while doing things, which is evident when he plays with people to make things more entertaining for him. He is also shown to have a slightly sadistic side as he will corrupt people to fulfill his goals and take pleasure in doing so. He plays with people's emotions and pits them against each other for his laughs and has a tendency to be on the flashy side although still subtle with his plans.
He has a extreme dislike for humans as he sees them as disgustingly idealistic creatures. He thinks of them as nothing more than rotten creatures who deserve the emotions they are inflicted with. This seems to go hand in hand with his interest in corrupting them as they loose the peaceful ideals they had and accept the darker truths.
Cerebrum may also have a soft spot for his fellow daemonia, he tried to look over the future of his kind by mating with Akari. However his plans later failed he still seemed to try to do the best he could for his species so that they could have their own forms as well withouth relying on bacteria. This may be influenced by his free will which is not found in most other daemonia.