Only the most evil departed souls become sinner demons, such as those of Shoko Asahara, Jim Jones, Adolf Hitler or Myra Hindley. They are compleetely iredeemable and do not have any chances at redemption.
Sir Pentious and Angel Dust are sinful departed souls (ghosts) who did not commit any serious crime that would make them irredeemable, such as murder, so they still have a chance at redemption.
Examples of sinner demons:
Minerva "Mimzy" Carabelli [1886-1926] (Sloth) (Italy)
Sins:
Fraud
Torture
Ordering murder and torture by proxy
Financing slave and child labor
Neglect
Corruption
Abuse
Money laundering
Minerva was part of a reputable Italian mafia, moving to the USA with her husband to continue their heinous work. She lived lazily and selfishly, living off of her husband's jewelry factory, which was powered by slave labor. Speaking of slave labor, Minerva had somewhat of a sadistic side and actually enjoyed torturing said slaves for fun, physically or mentally, whether they broke the factory's rules or not. She was also close to Alastor, helping him not only with his money-making schemes, but also with manipulating and scamming people. At the age of 30, Minerva was suddenly murdered by one of the factory's many disgruntled workers.
Victor "Vox" Evans [1943-2021] (Envy) (England)
Sins:
Fraud
Coercion
Manipulation
Sabotaging
Theft
Corruption
Ordering murder by proxy
Being the founder and CEO of the tech company VoxTek (founding it in 1974), Victor was never a very honest chairman. Growing up with a busy family that never had time to congratulate him for his accomplishments and focused on his siblings instead, he was always envious of others, becoming very competitive with rivals. This resentment carried on to his adulthood, as he ordered his employees to sabotage Voxtek's competitors and went as far as hiring hitmen to murder other CEO's. After decades of sabotaging and fraudulent acts in order to get Voxtek to a net worth of billions, Victor was eventually caught in 2006, ending up in jail and having his company shut down. With barely any pennies and behind bars, he died at the age of 78 from colon cancer.
Valentino Paz [1936-1977] (Greed) (Mexico)
Sins:
Psychological abuse
Treachery
Fraud
Blackmail
Theft
Money laundering
Ordering murder and torture by proxy
Coercion
Corruption
Sexual harassment
Sex and drug trafficking
Born in extreme poverty, Valentino grew trying to climb the social ladder in an honest way, but gave up once he realized how often he was taken advantage of. In an attempt to have a better life, he entered the world of crime, starting with drug trafficking and ending as a cartel leader and corrupt owner of a large porn studio, moving to the United States. He also enabled sex trafficking, having a good chunk of his actors and actresses being unwilling participants. However, his life had a sudden end at the age of 41 once Mexican authorities found out about his whereabouts and the police raided his studios, shooting him dead as he was trying to run away.
Isaac "Alastor" Miller [1873-1929] (Pride) (USA)
Sins:
False advertising
Compulsive lying
Manipulation
Mass fraud
Medical quackery
Treachery
Theft
Money laundering
Corruption
Isaac, coming from a family of African-Americans who used to be slaves until 1865, was always shamed by others during his youth for being black and poor. As a consequence, he became desperate to become worthy of respect, fantasizing about becoming rich and powerful. This desperation grew so much he started to take advantage of others in order to get easy cash. He grew rich having a con artist's career through medical quackery and promoting his products through the radio. Trying to abandon his past to the point of shaming and taking advantage of the poor - even when he was on their position once - the future radio demon even targeted terminally ill people who really wanted a beam of hope to shine on them, only to get them bankrupt and leave them to die. However, he was later hit by karma, as he suddenly died from tuberculosis at the age of 56.
Hiromi "Niffty" Yasuhiro [1924-1958] (Wrath) (Japan)
Sins:
Framing
Serial murder
Psychological abuse
Child murder
Child abuse
Torture
Hiromi had a tragic backstory as a comfort woman during World War II. Being an unwanted child, her mother sold her as a prostitute to the Imperial Japanese Armed Forces in 1941, when she was only 17. Those four years would change her life, as if she was in Hell while still alive. After being rescued in 1945, Hiromi tried to live a normal life in medical school and follow her dream become a nurse, but her trauma got in the way. Mindbroken, she started to find pleasure in torturing and killing male patients, no matter their age or condition, along with falsely accusing others of rape just to watch their lives get ruined. In 1956, she was later (literally) caught red-handed by police during one of her acts and put on death row. Being calm and prideful during her trial, she gleefully claimed to commit over 200 murders and cackled maniacally when she was asked her motive, telling the judges a chilling phrase: "This shitty country has robbed the humanity of many women like me, and now you have to bear the consequences". In 1958, at the age of 34, before she could get executed, Hiromi was eventually found dead inside her cell. She committed suicide by hanging and had written "see you in hell" on a wall.