Acheval Dreissen

About
Acheval Dreissen was a Zero Knight of Eden. Born to Tank Dreissen and a Zero Knight mother, Acheval was raised in the town of Stallion, along with his sister Ramius. He was promoted to Zero Knight following his performance during the Arthur Tragedy, and continued to defend Eden from monsters in the years that followed.

Unknown to his allies, Acheval was not a truly loyal servant. Having discovered his mother had escalated the Arthur Incident into a bloodbath, he was forced to kill her, only to discover he had inherited a similar, unshakable desire for battle. Unwilling or unable to confront these urges, he agreed to join the Snake Crest to create a world of eternal conflict where he could indulge them, but asked Millet to keep him under mind control so that he could keep up public appearances. In his moments of lucidity, Acheval transformed into an even more powerful warrior, the Black Knight.

As the Black Knight, Acheval assisted the Snake Crest in its efforts, but also frequently allowed their plans to go amiss, in some cases due to inaction from his overwhelming sloth, and also the desire to see Aster and his sister become stronger so that he could challenge them in battle. Having assembled a team of partially-trained adventurers (Gajel, Hellbell, Momiji, and Paraly), Acheval met Aster and his wives in battle on the Battleship Digamma, where he was defeated and killed. Before his death, he made a full confession, and found peace upon realizing Ramius was free of his family's bloodlust and happy with her new family.

Personality and Appearance
In public, Acheval put on a boisterous and loud personality, and is generally a positive person, happy to spend time with his friends and to seek challenge in battle. As the Black Knight, however, he allowed his malaise to take over, seeking battle alone and showing minimal concern for larger goals. Seydes secretly used Acheval as a means of cultivating this overwhelming sloth and complacency, and used it to empower himself.

Acheval's relationship with his sister, Ramius, was extremely complicated. He tried to discourage her from becoming a knight to spare her the bloodlust he believed he had inherited from their mother, but (perhaps due to his sloth), did so in only petty, bullying ways, giving her serious self-image problems and discouraging her relationships, but not discouraging her from being a knight in the slightest. Acheval had a deep respect for Aster, partially because of his genuinely strong relationship with Ramius, which led to Acheval's single-minded dedication to battle his brother-in-law.

Acheval recognized the value of having a team more than nearly any other member of Snake Crest, but was too slothful to put in the effort to actually train them to efficiency. Between his sloth, his schedule, and his need to conceal his membership with the Snake Crest, Acheval never attempted to marry.

By his own admission, Acheval was a terrible liar, to the degree that he needed mind control to hide his allegiance to the Snake Crest.

Abilities
Acheval was a Zero Knight, marking him as one of the most powerful warriors on the World of Eve. This ranking enabled him to kill anyone from a species protected by Mother Eve's blessing without becoming an Outlaw, and to marry at least ten other people, though it is possible that he was given further promotion to allow for more.

In both his base and Black Knight forms, Acheval showed a mix of offensive and defensive techniques, but not much in the ways of finesse, possibly a byproduct of his bloodlust.

Acheval's Black Knight transformation caused the armour of the Dark Knight to actually come out from beneath his skin, possibly implying that he has outright become a metal being in this form. As the Dark Knight, his powers were greatly enhanced, though the particulars of how he acquired the form and what it could do are unknown.

Trivia

 * The Black Knight is one of only two "sinners" used by Seydes who does not appear in the Archfiend's Right Arm as a Shadow. This may be because he ultimately found peace before his death. The other exception was Ophelia.