Chandler is a high-ranking demon and the former master of Meliodas, the captain of the Seven Deadly Sins. Known as the Pacifier Fiend, he is a powerful sorcerer whose true nature is deeply connected to the Demon King. In reality, Chandler is one half of the Original Demon, a being the Demon King split into two separate entities, with the other half being his comrade Cusack.

In terms of background, Chandler served as Meliodas's personal combat instructor long before the ancient Holy War. He was eventually sealed away along with the rest of his clan but was unleashed during the conflict surrounding the Ten Commandments. His primary motivation is an obsessive, possessive affection for his former pupil. He dotes on Meliodas, referring to him as "young master," and his love for him is so extreme that he disregards Meliodas's three-thousand-year-old betrayal of the Demon Clan, instead blaming Elizabeth, the goddess who became Meliodas's lover, for corrupting him. This devotion drives him to seek out Meliodas and attempt to bring him back to the demon side by any means necessary, while harboring a fierce and murderous hatred for Elizabeth, whom he sees as a source of weakness.

Chandler's role in the Imperial Wrath of The Gods arc is that of a major antagonist and an overwhelming obstacle for the Seven Deadly Sins. He first appears before the Sins by shrouding the entire region in true darkness, a magical night that nullifies the power of Escanor's Sunshine. Upon arriving, he easily dismantles their defenses, using his mastery of magic to counter and overwhelm them. He demonstrates his power by shrinking Diane with a spell called Microscopic and effortlessly deflecting attacks with his own version of Full Counter, the technique he originally taught to Meliodas. The Sins manage to temporarily subdue him through a combined effort, but when he believes he is losing Meliodas, Chandler undergoes a dramatic transformation, reverting from a stout old man into a young, muscular, and winged demon with a concealed sword in his cane.

His key relationships are defined by this central obsession. His connection to Meliodas is that of a proud and fanatical mentor who cannot accept his student's change of heart. In contrast, his relationship with Cusack is one of a peer, as they are the two halves of the Original Demon. While they work together, Chandler is shown to be envious of Cusack's good relationship with Zeldris, Meliodas's brother. His interactions with the other members of the Seven Deadly Sins, including King, Diane, and Ban, are purely combative, as he views them as irrelevant insects standing between him and his goal.

Chandler shows little to no character development in the traditional sense, as his nature is fixed. However, his role in the story does evolve. After being pushed to his limits by the Sins and their allies, he is forced to reveal his true form, showcasing his full terrifying power. Later in the overarching narrative, his loyalty to Meliodas leads him to try and collect the Commandments so his pupil can become the new Demon King, a plan that ultimately leads to a fatal confrontation not with the Sins, but with his other half, Cusack.

Chandler possesses a formidable arsenal of abilities, granting him an extreme power level that surpasses the individual members of the Ten Commandments. His magical power is known as Punishment, and his signature technique is Full Counter, which reflects any magical attack back at the caster with greater force. He can also use Absolute Cancel to dispel any spell and Absolute Order, which forces a target to obey his commands or die. For offense, he commands spells like Meteorworks to rain down fireballs, Crimson Requiem to generate intense heat capable of melting giant armor, and Enkonjin to fire blades of magical energy. When he enters his true, younger form, all of his physical capabilities skyrocket, granting him immense speed, strength, and resilience, allowing him to fight entire groups of high-level warriors simultaneously.