Kid Karnevil, an adolescent Torture Technician first introduced in Shadowpact. He claims to emulate the Joker and ultimately wants to kill him. Old Greenhair is unimpressed.
To wit though, it's rumored that the Kid actually died at some point and was sent to Hell. However, he was kicked out some time later, apparently because he was scaring the employees.
Lucifer, to no-one's surprise, would be considered a sociopath by human standards. He isn't one (human that is), and neither are many of the comic's other sociopathic characters.
Lex Luthor is often described as being a sociopath, and he has done many heinous things without remorse— including killing his father for startup capital (granted he was a textbook abusive father, too), curing his sister's disease then giving it back to her just because he could, strangling a black belt martial artist just because she had the gall to beat him in training, and (implied) letting a biochemist-turned-superhero die to give Superman a Heroic BSoD. Also, his (Post-Crisis) motivation for hating Superman? Because he exists, and Luthor doesn't want someone more powerful than himself around.
Brainiac has absolutely no capacity for feeling emotions and generally couldn't care less about anyone else other than himself; the only thing that effectively motivates him is his own desires and interests and he doesn't give a damn about having to destroy planets and civilizations and kill billions of lives simply to harvest something to add to his collection. On the rare occasions that he does have an emotional reaction, it's either sadistic glee or panic and rage over being defeated and being interfered with. All of these make a harrowingly dark mirror to Superman; while the Man of Steel is a symbol of hope and inspiration, Brainiac, in what can be considered the total opposite, is nothing more than an omnicidal, sociopathic monster.
Darkseid is a cold, remorseless, and brutal being who desires cruelty and misery towards all others and he will do whatever it takes to extort that. He possesses no sense of personal affection for anybody (at least after Suli's death), will make it a goal to assert authority to his subordinates and slaves in the most abusive manner possible, particularly towards Kalibak, has a grandiose sense of ego and will constantly twist his words into manipulating others with no care, only to stop occasionally, simply to gloat to them about how they fell for his machinations. Whatever sort of interest he has towards anybody is only determined by his standards of what is worthy and commendable, otherwise, anything and everything can just be destroyed or subjected to agony.
As we find out from Watchmen, The Comedian. Although, interestingly enough, the Comedian is ultimately capable of realizing that what he did was wrong - he admits to doing "bad things" during his Villainous Breakdown to Moloch. Rorschach on the other hand is a Sociopathic Hero.
Terra (the first one from the 1980s) from Teen Titans fits this trope to a T. She absolutely hated the Teen Titans, and gladly betrayed them in a story-arc which is still famous today, known as the "Judas Contract."
Vandal Savage has no value for human life and lives primarily for any cause or deed that can stimulate him.
The Joker is often considered the best Batman villain. He's also the most monstrous and dangerous of the lot. Aside from committing almost every villainous act that a human can pull off either to prove a sadistic point or For the Evulz, The Joker is also known for having no redeemable qualities whatsoever. He beat Jason Todd (then Robin) near to death with a crowbar just because he could, and permanently disabled Barbara Gordon in an attempt to make the Commissioner crack. He tried to kill Harley Quinn once because he was starting to remember what it was like to care and didn't like it; he only failed because Poison Ivy found her and nursed her back to health.
But that's not all, The Joker is so egocentric and uncaring that when he finds out that Harley Quinn (the only woman who genuinely loves and cares for him) has captured and is about to kill Batman, he beats her and knocks her out of the window and then proceeds to release Batman from Harley's trap— simply because his ego was too big to let anyone else (even his own lover) kill Bats.
This is one of the defining traits of Hush. Unlike Bruce, Thomas had a poor relationship with his parents, to the point that he murdered them both. He thinks Bruce is lucky that someone else killed his parents, and doesn't understand why someone might prefer having parents to having a lot of money. In addition, he knows that Bruce is Batman, and thinks that he does it for fun.
Wonder Womanvol 1: Queen Atomia is a remorseless, manipulative, power hungry tyrant who demands to be ruler of everything no matter how big or small and whose "subjects" are people she's forcibly transformed into mindless slaves. Not so much in her Wonder Woman (Rebirth) incarnation who was reimagined with a heavy dose of Adaptational Heroism.
Yellowjacket: R. Krause tortures people to death so he can figure out how to regenerate limbs and make a lot of money.
