Satan

Satan is the main quasi-antagonist of Puyo Puyo and Madou Monogatari series.

Appearance
Satan has long flowing green hair, pointed ears, a pair of golden horns that jet from his head and red eyes.

History
Satan was previously the owner of Carbuncle, planning to give the creature to his one true love as a showing of his devotion. Through happestance, Arle Nadja ends up with Carbuncle becoming it's friend. Satan, seeing as Arle has Carbuncle reasons that she must be his one true love and pursues her accordingly wishing to marry her.

When Arle reveals she's only interested in the treasure which happens to be a jewel in Carbuncle's head, Satan attacks her in order to protect Carbuncle's life.

Trivia

 * Satan's first love Lilith is revealed to look exactly like Arle in Madou Monogatari: Chaotic Final Exam, adding another factor to his obsession with Arle.
 * Satan has a great love for Hawaiian shirts.
 * In Puyo Puyo Sun, Satan increases the size of the sun to perpetuate an endless summer. His reasoning? Bikinis.
 * Satan's obsession with Carbuncle leads him to collect Carbuncle themed merchandise and in Puyo Puyo Champions, his alt outfit is even him dressing up in a Carbuncle onesie.
 * Fitting of a ruler of hell, many of Satan's magical abilities are named after words for disasters.
 * Whilst Satan is hopelessly infatuated with Arle, Rulue in turn is hopelessly infatuated with him. Despite not returning her feelings, they appear to be on good terms, although Satan has a habit of carelessly hurting her feelings.
 * After his initial appearance in Madou Monogatari II where he attacks Arle, he becomes less of a true antagonist and more of a nuisance to her as he desperately attempts to win her affections.