Blacksad: Jezebel in Arctic Nation was so deadset on making her white father pay for what he did to her black mother that anything was considered fair collateral. Even her twin sister. The irony is that her father left her mother to die because he couldn't stand the thought of having black children. Jezebel takes after her father's phenotype, while Dinah takes after her mother's, thus by being responsible for the events that caused Dinah's death, Jezebel inadvertently succeeded in doing what her father failed to do. Only Dinah's daughter Kylie remains in defiance of her grandfather's cruelty and her aunt's recklessness.
Alan Moore uses this to explain Hyde's growth and Jekyll's faltering health in The League of Extraordinary Gentlemen: Hyde was once smaller than Jekyll, but the longer they spent as separate entities, they changed. Jekyll became frail from his lack of passion, while Hyde grew due to his lack of limits. It fits Hyde's personality as well, as he joyfully commits hideous acts that give even the more bloodthirsty of his teammates pause.
It's also a carryover from the original novel, where Hyde is described as growing larger and stronger as Jekyll's evil side becomes more developed.
It is an interesting take to the concept that in Hyde's own opinion, in separating the animal primal nature from the civilized man, Jekyll has condemned them both. Hyde is unfettered because he has almost no fetters in himself at all and is losing what few still lingers, though he recognise that the process is making him more and more ruthless and risk-taking, and thus it will probably end by prompting his own death in some kind of mindless assault.
Shockwave is very much this. While Pragmatic Villainy can be relied upon to keep him somewhat in check, he will do anything from killing his Dragon to test a theory to slaughtering innocents who might help the heroes unravel his plans. His Evil Plans tend to be so far beyond what anyone else considers that they come out of left field; Plan 1, in The Transformers: Dark Cybertron, would have reduced the entire universe to a battery for Cybertron itself and essentially made Shockwave himself a god, while his second one involved manipulating the entire history of Cybertron. It's eventually revealed to be a Justified Trope: he was originally a good-hearted senator whose attempts at fighting injustice prompted his enemies to cut away the emotion and morality centers of his brain.
Prowl spends about four million years stuck in an endless cycle of being this, having a Heel Realisation, trying to better himself, hitting a setback, making sacrifices to overcome it and falling back into old ways. One of his less proud moments was the False Flag Operation where he faked a Decepticon terror attack, leading the survivors to enlist as Autobots. Then there's installing a backdoor into Kup's brain so he'd have a convenient mouthpiece who people would actually listen to. His old partner Mesothulas never moved on, or even tried. He goes to ridiculous lengths to try and get Prowl to talk to him again.
The Dinobots are an Unscrupulous Hero version. When they're upset at Grimlock for setting up a Deadmans Switch that ended up trapping them on Earth in stasis lock for millennia, without even telling them first, Grimlock bluntly tells them that that kind of tactic is what makes them Dinobots, and while they're still mad about it, they do concede the point and end up defending him against an army of Sunstreaker clones.
The Wreckers will go to any lengths to get victories in situations where the very concept of winning looks ridiculous. In The Transformers: Last Stand of the Wreckers, they go in with entire magazines of bullets that have been declared war crimes to use. More specifically, they're a deconstruction. The Wreckers aren't actually monsters, which means that those who do survive their missions tend to be traumatised by both the friends they've lost and the things they've done, and their growing ruthlessness leads to Impactor well and truly crossing the line by murdering their Decepticon opposite numbers in cold blood. Some manage to claw back at least some measure of stability the way, say, Impactor and Whirl do; others, well, by The Transformers: Sins of the Wreckers Guzzle has to be kept in a cell when not actively killing.
The Grand Architect goes to tremendous lengths to stop Functionist Cybertron, to the point of removing entire solar systems from the Benzene Cluster to make room for his "God Gun", which is five literal planets he's manufactured to fire a giant laser. Ironically, his efforts end up opening the path for Functionist Cybertron to break through into our universe, and it falls to the crew of the Lost Light to actually stop it.
