Clayman

Clayman (クレイマン) was a Demon Lord Seed who was a member of the Ten Great Demon Lords. He was considered a ghastly man, infamous for his acts of manipulating his subordinates and others like dolls.

Appearance
Clayman had an overall appearance of a wealthy noble. He had a slim, oblong head with a sharp chin and defined jawlines, having a pair of pointed ears on either side and thin eyebrows.

His getup involved a three-layered tuxedo, having an overall white color scheme.

When he put his mask on and acted as the "Crazed Clown," he seemed more like a mad beast instead. His entries body morphs into a dark color with a tail, six arms and armor on his legs and shoulders.

Personality
Clayman was a cunning and manipulative Demon Lord, preferring to manipulate things in the background rather than get into conflict himself. He specialized in intelligence gathering with the use of his ability in order to perfect his scheme to obtain more power.

Clayman treated his subordinates and those he considered below him very poorly, and would throw away those who were no longer useful to him and force others to submit using his unique skill.

He was also very stubborn and prideful, refusing to admit when he made errors that put in evidence his plots and every Demon Lord was aware of his conspiracy to become a True Demon Lord. Clayman also never liked to say his opinion of his fellow demon lords, when Milim was "mind controlled" only then he started to insult her and said his personal opinion of Milim, showing that Clayman was also a coward.

As seen in his actions and noted by his creator and comrades, Clayman was noted to be quite arrogant and overconfident in his abilities when things seemed like they were going according to his plan, as seen where he made several tactical errors during his plots against Rimuru and Tempest, such as assuming he had successfully mind controlled Milim despite her being infamous for being uncontrollable, assumed that Frey was his ally loyal to him alone and believed that he was powerful enough to overpower Rimuru and Shion due his supposed "control" over Milim. This personality trait was noted by both Kazream and Laplace to be one of his most prevailing traits despite their warnings for him to adjust it.

However, Clayman was very gentle and considerate towards those who he considered his friends and comrades such as the Moderate Harlequin Alliance. He also respected and followed his superior's order with absolute loyalty. This is seen during his final moments, when he refused to divulge any information on his superiors or his comrades during his final stand against RImuru despite being threatened with the complete and utter eradication of his soul, with Raphael acknowledging and calculating that it would be extremely difficult to get Clayman to talk.

Background
Clayman was created by "Curse Lord" Kazaream as a walking dead many years ago to be part of the Moderate Harlequin Alliance, known as The Crazed Clown. Kazream himself personally designed Clayman to be a tactical commander and a schemer, similar to himself and created him for the expressed purpose of turning him into a Demon Lord.

300 years ago, He became one of the Ten Great Demon Lords with Kagali's help. The moment he became a Demon Lord, he began hunting down Majin and monsters to steal their hearts (literally). Making them swear loyalty to him, he inscribed a curse onto their hearts, making them his eternal servants.

After Kagali was defeated by Leon, Clayman hadn't received any words from him for a long time, until he met a mysterious patron who offered the resurrection of Kagali in exchange of Moderate Harlequin Alliance's help in taking over the world.

Trivia

 * Despite being killed during the events of Volume 6, his name was still often brought up in later volumes as a benchmark to describe the strength/magicule amount of new characters. The author jokingly mentioned that Clayman effectively became a "combat strength measurement unit."
 * His VA in anime, Takehito Koyasu, is well known for playing twisted and manipulative evil masterminds, such as Dio Brando/DIO in JoJo's Bizarre Adventure and Sugo Nobuyuki in Sword Art Online. Needless to say, this is very fitting for Clayman's character.