- Complete Monster: Satan is the most powerful and wickedest demon of the Reverse Kabbalah. Formerly a scientist of Solomon called Lucifer, he helped to create the two Kabbalah to harness the universe's energy, which eventually absorbed his native planet and later caused the destruction of many others. Obsessed with power, Lucifer sacrificed numerous creatures to become Satan, but this caused him to lose his body so he decided to consume the bodies of the other scientists of Solomon, until he was tricked and his consciousness sealed in the body of human child Jio Freed. After landing on another planet, Satan caused several deaths throughout history and contributed to various mass extinctions, notably one provoked by Alucard Spirit. During Jio's childhood, Satan did everything to ensure he'd have a horrible life and corrupted him into hating the rest of the world to feed on his negative emotions. Around this period, he also ruined several people's lives to consume their hatred, killing Jin's parents and later murdering Cross's sister Lily, destroying their town in the process. During Jio's teenage years, Satan often takes control of his body, and usually attacks anyone present. In the city of Rock Bird, Satan takes full possession of Jio's body, absorbs Ruby's soul and tries to destroy the city. Years later, Satan initiates Armageddon to consume all living beings in the planet, but not before corrupting them all into turning against each other to feed on their hatred. He then plans to travel to another planet and become its supreme ruler.
- Cult Classic: Despite being called a ripoff, O-Parts Hunter is considered by its fans to be one of the few gems that should've gotten an anime
- Evil Is Sexy: Ponzu while holding the Lilith nucleus in her.
- Mis-blamed: See the whole bit about being called a Naruto ripoff. Apparently, people are shocked that twin brothers who grew up together and enjoyed the same things would have similar art and storytelling styles (even if the stories aren't that similar in execution). Much kudos to the mangazine that ran this series for keeping it going despite the controversy and Masashi for helping his brother out against the naysayers.
YMMV / 666 Satan