A more pitiable variant of the Super Soldier or Human Weapon, the Sympathetic Sentient Weapon is given increased combat ability by someone with power over them at the cost of their happiness and basic autonomy. The acquisition of their combat abilities is involuntary and often unpleasant or dangerous.
More often than not, some branch of Research, Inc. will be behind it - either For Science!, or for profit, and usually at the behest of their malevolent benefactor, as part of some sinister plot. Or it could be the result of any manner of shady business the victim wouldn't voluntarily be a part of.
Their enhancements make them formidable, perhaps even nigh unstoppable, but they're still under control of their masters and have no real way to refuse their commands, no matter how traumatizing or morally abhorrent. Because of the inherent risks of keeping traumatized Super Soldiers with multiple reasons to hate them, their masters often control them through some form of coercion, ranging from blackmail, Mind Manipulation or by outright making them mindless — often by way of cybernetic enhancements.
There's usually an element of dehumanization, as the victim is likely treated as a weapon, an expendable asset, or an Attack Animal rather than a human being. So expect them to be broken on the inside.
While this character is, by definition, in an unhappy situation, if they're sufficiently emotionally numb, under heavy enough brainwashing, or Conditioned to Accept Horror, they might not consciously realize how unfortunate they are.
There are multiple scenarios on how this is played:
- Alice the Dark Magical Girl was raised by the overlord to be a lethal Tyke-Bomb despite a kindhearted nature, leaving her a miserable Broken Bird who only fights the heroes because she is told to. The heroes know she can be saved.
- Bob the Elite Mook Cyborg is a Living Weapon who has no control over his own actions and laments he Was Once a Man, making him pitiable even as he tries to kill you.
- Carl the retired Super Soldier is haunted by the things he did in the war.
- Debbie was one of the hero's allies, but was captured by the overlord some time ago. Now she resurfaces with an Evil Makeover and a Restraining Bolt, as a Mook Lieutenant. The heroes know she can be saved.
See also Tyke-Bomb and Human Weapon. Subtrope of Made a Slave and Forced into Evil. Compare I Am Not a Gun, when this is lampshaded, and Woobie, Destroyer of Worlds. Henchmen Race combined with Woobie Species results in an army of these. Related to FaceMonster Turn which covers turning someone into something monstrous against their will with variety of reasons and methods.
- The cyborgs in Gunslinger Girl have elements of this, considering that they're young girls who didn't consent to any of this, and the side of effects of cyberneticization and associated conditioning will eventually cost them their personalities and lives. Unusually for the trope, some of them have horrific enough backstories that this isn't the worst thing to ever happen to them.
- The Asura Machina, armor-like magical beings, from Asura Cryin' are this, while they're usually formerly human beings who communicate with their handler via ghost-like astral projection, when summoned into battle, they went into a deep-sleep like state as the Asura Machina is summoned.
- Played straight for many Child Soldier characters in Naruto — that includes adults that had been Child Soldiers in their youth, dating back to the very first Hokage's time. However, it is sometimes inverted — the character is purposefully made The Woobie to increase his combat power through Traumatic Superpower Awakening.
- Variable Geo: Once The Jahana Group becomes aware of Satomi's immense spirit energy, they pressure her into entering the VG Tournament by going after her brother. Damian causes his condition to relapse, then offers to cover the procedure needed to cure him... on the condition that Satomi enter the tournament. She's left with no choice but to accept their terms and is subjected to the "Black Goddess" project, which turns her into a vessel for Miranda Jahana's disembodied spirit.
- Newtypes (and their counterparts in AU verses) in the Gundam metaseries are often this. They're usually Psychic Children who are forced to pilot extremely powerful units after being raised as soldiers or test subjects. They usually suffer mentally and physically from their powers, and a common storyline is The Hero befriending—or falling in love—with the Newtype and being forced to fight them.
- YuYu Hakusho. During the Dark Tournament, Team Urameshi encounters a team of fighters who had their minds suppressed as part of Dr Ichigaki's experiment they agreed to in exchange for healing their ill master and were subsequently turned into killing machines. Kuwabara via a psychic link could tell that they were suffering being forced to watch as they killed other people against their will and at one point they stopped fighting long enough to ask for Yusuke to kill them.
- In Neon Genesis Evangelion, the EVAs are human souls forced into mecha bodies and are forced to do horrible things for questionable reasons, regardless of what they want.
- This is revealed to be Oz's sin and backstory in PandoraHearts, as well as the true secret behind the Tragedy of Sablier. Played for both drama and horror with the reveal that he was the Chain that, under the control of a madman with no regard for anyone's lives, slaughtered and sank the city of Sablier into the Abyss. Entirely against his will. Oh, and those echoing tortured screams and pleadings to stop he heard in the ruins a century later? His own.
- In Attack on Titan, this turns out to be the true nature of the Colossal, Armored, and Female Titans. Their nation keeps their people in slavery, keeping them alive as fodder for their war machine and not even considering them human beings. Their families volunteered them for a Tyke-Bomb program as small children, having been promised their freedom in exchange. The children were subjected to Training from Hell and extensive indoctrination, then given a power that will kill them in 13 years. They were sent on a mission to exterminate the people living within the Walls, based on false promises and a made-up threat against the world. Over the years, Bertolt, Reiner, and Annie all begin to psychologically fall apart under the strain of their mission....but are unable to disobey their superiors out of fear for their own lives and those of their families. In the end, only Reiner returned from the mission, becoming a Shell-Shocked Veteran forced to "prove" his usefulness and loyalty by fighting on the front lines of a major war. Even after getting back into his superiors' good graces, he is left simply waiting for his superiors to pick his replacement and kill him. In a private conversation, he breaks down and describes being one of Marley's Warriors as a cursed existence with a "black future".
- The protagonists of WE 3 are a cat, a dog, and a rabbit who have been turned into killer cyborgs by the military. They are not happy with their situation, and this sci-fi plot device is used to address the larger issues of animal testing and animal rights.
- X-23 is a textbook example. She was cloned from Wolverine to be a Tyke-Bomb and has been forced to kill a number of people, including her mother and her sensei.
- In The Order, poor Mulholland Black was turned into a living WMD by the Black Dahlias.
- In the "Homeschooling" arc of Runaways, Klara Prast, whose Back Story included rape, physical abuse, and forced labor, lost control of her plant-controlling powers after an accident and managed to take out a squad of paramilitary thugs.
- When The Authority ran into an evil Captain Ersatz version of The Avengers, the Midnighter managed to talk the Iron Man equivalent away by making him realize he was this ("you're just a weapon with a larynx"). In the epilogue, he writes a letter thanking Midnighter for saving him, having found a home and a family.
- Captain America: The Winter Soldier. The Winter Soldier turns out to be Bucky Barnes, Steve's presumed-dead Heterosexual Life-Partner. HYDRA turned him into an amnesiac cyborg super-assassin. And it gets even more tragic from there. Not only is he being (essentially) forced to serve the organisation he gave his life to stop, but Captain America: Civil War reveals that he's also a Manchurian Agent — even once he's left HYDRA and assassination behind and regained enough of his memories to navigate his life, he's still forced to carry out whatever reprehensible acts the forces of evil want him to commit, so long as they know the correct trigger words. And activation appears to be something of a painful experience.
- Danny in Danny the Dog, with an emphasis on the dehumanization aspect, since he was raised as a brainwashed human attack dog.
- Darth Maul in Star Wars Legends most definitely embodies this trope, and is hinted to in current canon, as well.
- In Dragon Bones Oreg is a slave who is bound by dark magic to do everything his master orders him to do. Everything. Someone notices, after watching him fight, that he has been trained as assassin. Not so much a sentient weapon as a sentient swiss knife; he can do a lots of other things besides fighting. While he can materialize a seemingly human body, the dark magic his father inflicted on him turned him into the forsaken child in the Powered by a Forsaken Child castle Hurog.
- Discworld's Orcs in Unseen Academicals were an entire species of this in their Back Story. They're Super Soldiers, they're descended from modified humans, and they didn't want to be fighting in the hordes of the Evil Empire. Unfortunately, nobody remembers this, and they're wrongly seen as Always Chaotic Evil. (Mr. Nutt, the major orc character in the present day, is also a woobie but not a weaponized one.)
- In the Animorphs series the Hork-Bajir were peaceful, dopey race of herbivores that happened to be living incarnations of the Lightning Bruiser and Absurdly Sharp Claws tropes- making them the perfect shock troops for the Yeerks after being conquered and enslaved.
- The Unsullied from A Song of Ice and Fire: They are slave soldiers that are castrated, hooked on medieval magical steroids and put through a brutal regimen of training which most of them do not survive. They are also brainwashed to be obedient and personality-less. Much emphasis is put on how inhumane is their very existence and how Daenerys Targaryen did a good thing by freeing all Unsullied from slavery, encouraging them to develop personality and putting a stop to producing any new ones.
- Marsh from Mistborn: The Original Trilogy. Like all Inquisitors, he is inhumanly strong and fast, virtually unkillable, not to mention things like flying through the air thanks to Allomancy. But the process of gaining those powers was gruesome and while for some time he enjoyed autonomy, in later books he is controlled by cosmic entity Ruin, whose aim is basically to bring the world to ruin. He can still think on his own but most of the time he is fully under control of Ruin — and when it is busy somewhere else, he just stands in the middle of a plain, being slowly covered by ash. He is, however instrumental in bringing Ruin's ultimate downfall and in Wax and Wayne he is a legendary figure.
- River Tam in Firefly was a gifted young girl who got turned into a psychic assassin with serious mental health issues. Fortunately, her brother rescued her and is doing his best to help her, but she's still a pretty broken cutie.
- The version of Deathlok in Marvel's Agents of S.H.I.E.L.D. is just an average guy who is given killing powers by HYDRA, and is forced to use them on their behalf or else they'll kill his son.
- Doctor Who:
- Rory, a companion and Amy's Love Interest returns from being retgoned as an Auton. It turns tragic when his programming forces him to shoot Amy.
- The Cybermen, who are essentially Muggles enslaved and forcibly made to Take a Level in Badass. However, both of these examples are downplayed, since the Cybermen are more focused on Immortality than becoming living weapons, and Rory was brought back for espionage purposes rather than becoming a weapon.
- In Believe, there is Sean, a Tyke-Bomb from Project Orchestra who was being held in reserve because he lacked the emotional stability of the candidates ahead of him. Of course, with Bo having been rescued and Joshua stuck in a coma, Sean automatically moved to the head of the line, and it's clear that he's not happy about it.
- The Asurans in Stargate Atlantis are Nanomachines-based life forms that were created by the Ancients to combat the Wraith. As they evolved more human, they've requested to remove the Hate Plague from their programming, only for their creators to respond with wiping them out and erasing from history. They've survived, and decided to take their hate on Ancients' descendants.
- Star Trek: The Next Generation: "The Hunted", Roga Danar.
Roga Danar: My improved reflexes have allowed me to kill eighty-four times. And my improved memory allows me to remember each of those eighty-four faces. Can you imagine what that feels like?"
- In Bioshock Infinite the Handymen are disabled humans grafted into huge robotic suits and go into a berserk screaming rage when they attack you. However, the human is not in full control. If you listen very carefully, some of their screams are pleas to kill them and warnings to get away. Near one of them you can find a recording from his wife telling him she still loves him.
- Super Robot Wars Z: The Sphere of Leo grants its power from any machine as long as the user is in pain. After many millennia in battle it wants to not fight anymore and decides to reside in a human, specifically the original character Mail.
- Shining Resonance: It's unknown exactly how long Marion and her twin brother, Ette, were subjected to Joachim's cruel experiments, but she was the only one who survived. Joachim conditioned her to serve as his tool, by giving her enhanced speed and analytical ability. Thankfully, she was eventually rescued by Yuma and his companions.
- Painwheel from Skullgirls was a young schoolgirl who was kidnapped and turned into a monstrous mind-controlled cyborg Super Soldier. And boy is she mad about it!
- Most Valkyria in the Valkyria Chronicles series. They're highly sought-after by both sides of the Europan War due to the destructive powers they possess, but those that end up in an army's employ are treated more like weapons that human beings, often up to being referred to as "it". And that's the best case scenario. At worst, they're experimented on in labs (often from childhood) or used as living batteries. It's no wonder most of them are downright broken: Selvaria from the first game is a Love Martyr to the Big Bad, while Crymaria from the 4th game suffers from severe self-worth issues and a desire to be praised, along with not being able to fully control her powers. Noble Demon enemy general Klaus Waltz is the only one to call out her superiors for their treatment of her, and the two end up surviving and becoming a couple after the war.
- Grace from El Goonish Shive. She was created specifically to kill Damien (she has fireproof fur that makes her immune from his fire-based attacks, and special claws that reduce his healing factor), but is naïve, "bubbly", and hates violence.
- Gunther in Collar 6 was "Project Vojna," a Super Soldier prototype who was being conditioned into a mindless, remorseless killer. Unfortunately for his handlers, they pushed him too far, and he bolted.