The prequel plays this straight when Redcloak is horrified by his boss's plan to kill and zombify a woman's physical body, then feed the body to ogres while forcing her soul to watch.
While Redcloak will threaten human citizens to try and get O-Chul to talk, when he is certain that O-Chul knows nothing about the Gates, he lets them live.
The prequel also subverts this trope when Xykon initially says that as evil as he is, he can't do something as depraved as become a lich (a form of undead created by evil magic), then he suddenly reveals that he was only joking and has no objection to becoming a lich at all.
While he's more of a Punch-Clock Villain, The Monster in the Dark is a Big Eater with no apparent problem considering eating humanoids (but only if ordered to). He won't eat babies, though (including veal), though this is more out of the fact that babies aren't tasty at all and that he much prefers the slop and gruel that he's normally served.
When Vaarsuvius wipes out a quarter of the black dragon race, the fiends that gave them that power in the first place are shocked speechless. Even moreso because they, unlike V, know that the soul splice isn't actually affecting the elf's morality.
Belkar is generally a source of these, as his evil tends to be on a very personal scale. He implies multiple times that he wouldn't lie to harm the party if there was no humor in it (and indeed, actually has a cleaner track record for lying to the party than several of the good members) and finds everything about the High Priest of Hel using Durkon's body (Durkula) repulsive.
This trope is spoofed in a much later stick figure filler week.
And again when two demons are talking and one makes an off-color joke.
Chilus: You know humans! They're a bit late for school! Skip: "A bit late for school?" Chilus: A little tardy. (Beat Panel) Skip:Was that a "retarded" joke? Do you know my brother's handicapped? Chilus: Right, I'm sorry! That was very insensitive of me. Let me get my purse and make a contribution to your favorite mental health charity... What's this? My driver's license... Why, it says here I'm a demon! So [blows tongue at Skip] pbbtbbtbtbtbtbt to you and your retarded brother! Skip: Fine. We're demons. We're evil. Can't you have a little class? Chilus: You're a little late for class.
Parodied again not too many strips later when Dagon says that even his kind has higher standards than making unholy offspring half-breeds from Sanrio characters.
Hunter Ravenwood of Suicide for HireWouldn't Hit a Girl, though that doesn't stop him from killing women who pay him to do so. Evidence suggests he doesn't like to think of the clients as people at all. The rules of the titular business also include "Suicides may not result in the death of a third party" and "Children under the age of sixteen will not be allowed to kill themselves". A pregnant client is rejected for this reason, as they consider her foetus to be a third party and object to helping her escape responsibility for it.
Later, when confronted with a severely battered woman, he first wants to help her kill her abusive husband. Only when she can't go through with the act, despite getting clear instructions via two-way radio, does he help her kill herself. Later, the husband comes to SFH...and his death is not at all pretty. Unusually, Arcturus is as enthusiastic about this job as Hunter.
Zexion is a governor that invaded New Jersey, stole tax dollars just to prove he could, and would rather spend the state budget on blowjobs and Doritoes...but he really hates racist pancakes. It Makes Sense in Context.
Black Mage: Even though I am the incarnation of all mortal evils, I just don't have the heart.
Towards the end of the series, when they discover that even though they've grown incredibly strong throughout their journeys, Sarda flat out tells them that they'll never be a match for him, and he was still going to render their efforts nil out of spite.
Black Mage: That's messed up, Sarda.
Thief states that Black Mage has hit a new low when he hears his plan to get into White Mage's robes after she temporarily turns "evil" involving what he thinks is alcohol but may be paint thinner. When the other Light Warriors point out that it'll likely kill White Mage, Black Mage simply responds that the corpse will still be warm for a little while.
The random encounter monsters are horrified when Black Mage asks if they plan to eat them.
Random Monster: That's disgusting! We may be monsters, but we're not monsters about it!
Black Mage's reaction when Thief hatches a plan to charge everyone in the world extortionate fees for the weatherhere:
"That's...hold on." (sets Red Mage on fire again) "That's really sick, Thief."
Red Mage, an XP-obsessed munchkin who has learned a spell capable of destroying the entire universe and is only marginally more ethical than Black Mage, refuses to record how to cast Hadouken upon learning that it suctions some of the love out of the universe with every cast.
To put this in context, Minmax refers to Kin (the yuan-ti in question) as "it," and had just persuaded Dellyn, a higher-level character and professional goblin-hunter, to join him on his quest to kill goblins.
In the The Beast Legion, the shadow Nexus's second in command, Stampede, is ruthless when it comes to battle but carries a great sense of honor & loyalty unlike his master.
None of the Overfiends like Slade. None of them! Though not many inhabitants of Asgar have virtuous qualities, at least they don't kill their own allies for fun and curiosity while possessing a sense of sadism that even creeps out the other demons.
In probably the most literal example of this, Mal was consistently visited by demons trying to take her to hell for being evil, but when she started to attack those who butcher the English language, Satan told his minion to leave her be; this is a justified attack.
In a recent state, Mal ends up doing shots with her friends while watching Disney movies and ends up conquering Disneyworld with the help of costumes granting superpowers and offering the employees dental coverage. Her intoxicated conquering self is perfectly accepting of Snow White's ability to control animals, Megara using Hades' powers because it's the same movie, Belle being able to turn people into furniture and use her magic mirror for surveillance, Aurora being able to put anyone into a deep sleep, and Mary Poppins having a bag that came in handy for carrying all the weapons. But after a demonstration of Alice from Alice in Wonderland's power, she made her sign a contract to never use or speak of it again. The other ladies only know that it involved Hearts.
Karkat's universe's version of Jack Noir is just as much an Ax-CrazyKnife Nut as any other version. But even he thinks that Karkat's angst over his "candy-color blood" is one of the saddest things he's ever seen and becomes Karkat's Blood Brother out of sympathy.
Jack Noir, the one from the kids' universe, is an Omnicidal Maniac who destroyed a whole universejust because. When Lord English destroys a dream bubble, all of the souls inside, and possibly some of the very fabric of space and time itself in one shot, all Jack can do is stare in shock and fear.
Meenah. Alternate universe teenage version of the Condesce. Fangirls over stories of said monster's deeds. Tries to kill Roxy when she first sees her, for no reason except just 'cause. Draws the line at picking on Mituna.
And her fangasm over the Condesce cracks badly when she finds out what she did to Mituna's counterpart.
Gamzee may be a Monster Clown, but even he thinks Jane's Trickster Mode is really disturbing.
Whilst The Golden Rule and "if you don't have anything nice to say" may not exactly be a cornerstone of Alternian society, there is still the understanding that cooperation is important — particularly because it is necessarily trait for battling other teams.
Caliborn may be a psychopath that delights in others' suffering, but even he is terrified of Lil' Cal, and one of the only times he gives actual, heartfelt advice to the main characters is to tell them to get rid of the puppet right this instant, as he believes it's a juju that brings calamity upon anyone near it. Turns out Lil' Cal is so dangerous because it's essentially Lord English's (Caliborn's future self) Soul Jar. When he learns that, his attitude toward Lil' Cal takes a 180 and he becomes gleeful at the suffering it causes.
El Goonish Shive:Even pitch-black evil guyEven Maguswon't help Chaos ruin Verres to just to kill Abraham just to punish Raven for being a disobedient son.
Also, during Painted Black, Hedge did everything in his power not to bring women back to Damien, knowing that he only wanted them for breeding and didn't give a damn about their consent. Once Damien was no longer around to control them, all of Grace's brothers surrendered without a fight.
More along the lines of "Even Jerk Ass has Standards" with Tony:
He later finds out his associate has been sabotaging his research, preventing him from finding out that the process could have been done without human hosts. He's appropriately mortified.
Kowalski, one of the Toughs' recurring enemies and Admiral Emm's personal wetworks specialist. He's someone who has little problem hijacking bodies of innocent people to commit mass murder with, but even he starts to find his admiral's increasingly extreme causes to be unnerving, especially the fact she'd be glad to have more like him. This eventually culminates in him just shooting her dead after they've both escaped to untraceable bodies, tired of killing for her causes.
During the Storm of Souls arc, Celesto Morgan refused to ally with the Chosen, considering their wanton destruction too much for his tastes. He only agrees to help get revenge on Dominic.
Kolonel Haken in Irregular Webcomic! may be a card-carrying Nazi, but he will not stand for genocide - he's an archaeologist, not a mass murderer. Eventually, he assassinates Hitler by stuffing a very large frog down his throat. Only in one webcomic could you find a sentence like that, folks.
The webcomic series, Lessons of Dogworldhas this issue, with one character being scolded by three others, one of them in this issue depicted as a demon, who too is upset about a person being denied help.
Skewed to the point of parody in Sonichu - in issue 10, Chris and some of his Sonichu allies attack the 4-cent Garbage building with music. In the process, Jason Kendrick Howell and a demon called Beel pull a Screw This, I'm Outta Here!. When Beel leaves, he claims that the two remaining people with them, Clyde Cash and Jack Thaddeus, were unimaginably evil that it paled in comparison to his time working with Hitler. Their crime? Being gay and being a troll.
In Terra Sovereign Northazul Kalar, the Evil Overlord of the piece, rejects his son Solus' request to launch a biowarfare attack against the United Earth Coalition on grounds that it would be dishonorable.
In Something*Positive 1938, the Affably Evil "Pops" Bernerd has almost certainly been involved in murder (or at least covering it up), but when Davan balks at drawing porn based on the characters from Little Orphan Annie, Bernerd clarifies that he's not asking him to draw Annie herself, and if he did, Bernerd would beak his arms.
In Terinu, the Gene Mage, the series' Big Bad, who is responsible for genetically engineering a Slave Race and aiding in the invasion of the Earth 500 years before, reacts angrily to one of his allies leaving two prisoners alone in a cell without food or water for several days.
Genocide Man: Joey is a sociopathic, fight-crazedold man of a Super Soldier, who gleefully takes on his assignments as one of the titular genocide men. However, when asked to vote on whether to release a bioengineered plague that would supposedly hamper humanity's violent, sociopathic or just generally harmful tendencies, he vehemently refuses, reasoning that would be "taking the teeth out of the human race, ensuring scrappers like me are never born again". Lampshaded by the Genocide Men's boss, who mutters she wasn't expecting such a refusal.
Bangladesh Dupree comes across as an Ax-Crazy homicidal sociopath. However, she hates mind control with a passion. Kill someone? No problem! Destroy whole towns and cities? Sounds like fun! But no mind control around her, not if you like living!
She also apparently detests being lied to...enough to even scare Gil.
Even the Heterodynes of old, epitomes of the Spark in both power and madness, weren't insane or reckless enough to mess with time more than once. The Castle itself remarks on this, and despite its insatiable taste for chaos and carnage approves of this precaution. He even briefly calls out Baron Wulfenbach (not that he could listen) for surpassing them in recklessness, by way of triggering a Timestop with no actual way of restarting time, with the consequences that brings.
The Jägermonsters share Bangladesh Dupree's attitude towards mind control. They may be sociopaths with a love of Rape, Pillage, and Burn, but when someone suggests that they might come under control of the Other, they emphasize that they took the Jägerdraught of their own free will, and serve the Heterodynes out of loyalty, not out of compulsion.
In Full Frontal Nerdity the players' characters open a restaurant serving the remains of the monsters they slay as "gourmet". But when they swipe some dragon eggs to make dragon "veal" the monster bones that were used as construction materials for their restaurant spontaneously reanimate and take the eggs back.
In The Non-Adventures of Wonderella Hitlerella, if you couldn't guess from the name, is a literal Nazi and Wonderella's archenemy, but even she thinks it's bullcrap that people have to work on Thanksgiving and is uncomfortable with Wonderella using the word 'retarded'.
In Supervillainous Crimson Claw is a badass villain who enjoys tormenting heroes, employs actual evil spirits, and once forced a man who annoyed him to move to a frozen tundra. Harming a legitimate charity, though, is strictly off limits, even when their offense was marketing action figures of him full of heroic quotes.note He does, however, buy up and gleefully incinerate the toys themselves.