Hiroim: Impossible...Our hero has acquired a new onboard superpower through the power of an origin story or receiving Applied Phlebotinum. Unfortunately, the effectiveness of the power or device depends on the mental stability and/or confidence of the user — and it's all too often an inverse relation (though not always). Inherent to The Dark Side. Naturally, tends to be an example of Personality Powers. Not to be confused with Psychic Powers or powers from psychoactives. Compare Heroic Spirit and The Power of Love, which may overlap with this trope.
Caiera: He shifted the very plates...
Korg: Of course he did, he's the Hulk.
Caiera: But you said he couldn't.
Korg: I was just making him mad. He seems to work best that way.
Caiera: He shifted the very plates...
Korg: Of course he did, he's the Hulk.
Caiera: But you said he couldn't.
Korg: I was just making him mad. He seems to work best that way.
- Tengen Toppa Gurren Lagann. The mecha of the series, called Gunmen, are powered by Spiral Energy, which comes from living things. The amount of Spiral Energy one produces is tied directly to their emotional state. Fear and despair lower it, hope and optimism increase it, and Hot Blood blasts it to Over Nine Thousand.
- Haruhi Suzumiya fits here. Of course, Haruhi doesn't know. It specifically depends on mental instability, and the rest of the cast spends a great deal of effort preventing this.
- Neon Genesis Evangelion
- The Lambda Drivers that power the Humongous Mecha in Full Metal Panic! work like this. The technobabble basically stated that it runs on Applied Phlebotinum that begins generating energy when exposed to brain waves above a certain level, which are reached when the brain is processing especially intense emotion.
- The bad guys found a way around this, by using a drug to keep their Lambda operators at peak emotion at all times. Has some side effects.
- Orihime's abilities in Bleach are restricted by her willpower. Her powers could be very powerful offensively she wields them by willingly rejecting reality if she actually wanted to hurt anyone, but she's an Actual Pacifist, and so generally only uses them for healing or defense.
- The N.O. portal connecting Medica Mechanica to Naota's head seems to get wider during times of emotional distress.
- In YuYu Hakusho, Kuwabara is undoubtably the weakest of the heroes, but has proven capable of short bursts of incredible power when properly motivated/inspired.
- Soul wavelengths in Soul Eater. Mindset affects both the powerful moves that require a high level of soul resonance between meister and Weapon, and the basic ability of the two to work together.
- Goku of Dragon Ball. When the chips are down, he'll take a beating and be on the ground battered and bruised — but The Power of Love is Goku's secret weapon. Remind him his loved ones will suffer if he doesn't get back up, and he'll find hidden reserves of strength and deliver a curb stomp to the bad guys.
- It's true of his son Gohan even from childhood. As a small boy, his power level is pathetic when he's scared but when he's angry it climbs and keeps climbing, enough to nearly knock a full blood Saiyan off his feet.
- The I-field barriers used by the SUMOs in Turn A Gundam are said to operate at least partially on the pilot's willpower (which goes a long way to explaining why Harry Ord's is so strong). The Moonlight Butterfly will also only manifest when the pilot has the proper amount of determination to activate it.
- The Gundam Unicorn's NT-D system only activates when the pilot is under a certain amount of emotional stressnote ... typically anger or fear (common battlefield emotions), but Banagher manages to activate it in episode 4 through determination to help someone. Later on he seems to be able to activate it at will discarding all previous limitations on the system.
- Before the I-Field and the NT-D, there was the Bio-sensor of Mobile Suit Zeta Gundam and Mobile Suit Gundam ZZ, which were miniature psycommu systems that were meant to just make the suits easier to control. Instead, they ended up making the machine's stronger through their pilot's anger. For Kamille Bidan, he made the Zeta powerful enough to turn a beam saber into a massive beam whip, then gathered the souls of the dead to fuel a kamikaze attack! For Judau Ashta, he was able to recombine the Double Zeta and super charge its Hi-Mega Cannon to the point where it actually melted the V-fins on the head.
- Dragon Slayer powers work this way in Fairy Tail. Happy actually revs Natsu up into beating a Big Bad by suggesting he should back off and let Gray handle it.
- Chaos;Head has the Di-Swords, only functional through... delusions. Thus, in somewhat of a departure from the classics, the user has to be screwed up in order to use the weapons. This, though, is only fitting in a show such as Chaos;Head.
- That's how the power of a Pretear works. The Pretear has the ability to create Life Energy, but her abilities may fail her if she loses the will to fight... and if she gives in to her dark side, her power can reverse completely, turning her into someone who absorbs life energy instead of generating it.
- While the powers in Psyren are mostly concentration/instinct-based Psychic Powers, there is emotion-fueled Psy... which are as dangerous and unstable as they are powerful. The key to normal psy is concentration, imagination, and careful control over your energy; emotion-based powers are prone to running rampant and over-stressing their users. The only other known user of the protagonist's psy died slowly from it degrading his health, and alone because his increasing distress made it manifest more often, which in turn distressed him further and made his health degrade even more.
- The Aquarions from Genesis of Aquarion and Aquarion Evol act this way: they require three pilots, each of them possessing a supernatural "Element" power. If any one of the pilots loses the will to fight or is otherwise out of sync emotionally with the others, the Aquarion will fail and split into its component pieces. The Aquarion's power is also directly related to the intensity of the emotions its pilots are feeling: the stronger the emotions, the stronger it becomes. Naturally, it's at its most powerful when love is involved, though interestingly enough, it can use negative emotions like hatred, jealousy, or even despair as power sources without any ill effects.
- Empowered: Emp's theory about her suit being shredded easily because her self confidence and self esteem are easly shredded is entirely accurate. When she's not thinking about ending up in Distressed Damsel territory, she can make really effective use of the suit. It has recently been confirmed that Emp's powers can be shut down by someone making her think about being tied up.
- The Green Lantern Ring - if the user doesn't have a strong will, getting the thing to so much as light up is a herculean task. If the user has a decent will, they'll be able to create constructs, but they won't hold up well in battle when the user is frightened or rattled. If the user doesn't have much of an imagination, it forms very boring and mundane things.
- And now there's a whole spectrum of colors that require feeling or inspiring a specific emotion (rage, greed, fear, will, hope, compassion, love) in order to work. Though the compassion rings tend to get around this little caveat by forcing their wearers to feel nothing but compassion.
- As of the Captain Britain and MI13 series, Captain Britain's powers work like this; super strength and durability in proportion to his confidence and emotional stability.
- Gladiator, AKA Kallark, of the Marvel Universe, is like this; his power is based on his confidence. This spirals both ways; being the most powerful mortal in the universe when he's on top of his game, he's ever-more-confident when things are going his way- but when something finally does go wrong for him, the shock can make his power collapse quick.
- Spider-Man's powers have stopped working several times due to emotional issues, in almost every medium that he's been in. He gets them back when he becomes self assured again, usually just in the nick of time. Inversely, when people he cares about are in danger his powers grow exponentially stronger.
- The Incredible Hulk. Bruce Banner only turns into the Hulk when angry, and then the angrier Hulk gets, the stronger Hulk gets.
- This does depend on the writer; sometimes the Hulk's transformations are portrayed as the result of adrenaline, both in the form of anger and excitement or fear, other times it is portrayed as a pure survival mechanism, activating to save Banner's life regardless of emotional state. But the anger fueling strength connection is generally maintained.
- She-Hulk (Jen Walters, that is) can usually use her powers at will, but she has been stuck before in her Hulk form due to subconscious unwillingness to change back, and in her human form when she was too scared to become She Hulk again. If you make her angry enough, she can also turn into a Savage She Hulk that is very reminiscent of he cousin's form.
- Superman once lost his powers for a year, then got them back when he cheered up and enjoyed his life.
- In Marvel the superhero Speedball, after becoming Penance, found that his new powers only worked when he was in pain. Cue the iron maiden styled combat suit. Except, Warren Ellis realized that people who cut themselves process pain abnormally; the adrenaline rush of self-mutilation triggers an endorphin reaction, in effect making them high. Thus, his powers have the same trigger as always; he can't use them unless he's happy. As the Fun Personified character he had been before Civil War, it makes some sense that this had previously not been noticed. Doc Samson points this out, and in the process helps him start overcoming his depression.
- In Child of the Storm, Harry's powers tend to be along the lines of this: especially the Super Strength, which only kicks in when he's afraid/angry, because of the adrenalin rush. His Psychic Powers are, at first, also along these lines, and still tend to flare dangerously if he's knocked for an emotional loop. This can be downright dangerous for him and whoever is around him.
- Chapter 5 of Savior Of Demons reveals that Frieza, and all Arcosians, have a very mild venom that only activates when they're terrified, which becomes a plot point because it paralyzes Goku's right hand...meaning that he can't use Shunkan Idou until it's treated.
- The Self-Insert Orange Lantern's power in With This Ring is dependent on much Avarice he feels: meaning it gets more powerful the more he wants something or how it can benefit him. If it doesn't benefit him or he only wants to help, the ring won't work. If he doesn't want it or outright hates it, he risks the ring destroying it.
- Will Stronghold of Sky High was in the gawky, awkward stage of adolescence, and had no confidence. He also had no powers, but hadn't made the connection between the two. The fear and shame involved in the idea of disappointing his superhero parents also didn't help. But when Warren put his friends in danger, Will grew confident and his powers suddenly manifested in the middle of the fight.
- The male lead in My Demon Lover only transformed into his formidable demonic aspect when he was horny enough.
- In In The Name Of The King: A Dungeon Siege Tale, the Big Bad Gallean goes mad with power and gains abilities not normally available to the magi. During his magical duel with Merick, this is the only thing that allows him to surprise and defeat the more experienced magus.
- In X-Men, in a blink and you'll miss it moment: Storm is knocked down an elevator shaft. She rises out of it flying with her trademark all white eyes, and delivers her line to the Toad about what happens when a toad gets struck by lightning. This is an obscure reference to the fact that in the comics, Storm is extremely claustrophobic, and the ensuing panic that causes often amplifies her powers beyond normal levels.
- In X-Men: First Class, Erik's control of his abilities is directly linked to his emotions.
- In X-Men: Days of Future Past, Charles can't control Cerebro until he gets some advice and encouragement from his future self and stabilizes emotionally, after which he's fine.
- One of the stories in the Azazel series by Isaac Asimov involves an irritating atheist given a Jetpack and told that it's powered by his belief in science and logic. The problem is, those who see him flying call it a miracle, and convince him it's one too, making him incapable of using it again.
- Skeeve in Another Fine Myth must stop drawing upon his parents' or mentor's strengths for his confidence, and find it in himself instead, to finally light a candle with his magic.
- Wild Cards: The school of thought that Aces are internally confident and end up being beautiful and powerful, while Jokers have some sort of internal self-hatred that manifests outwardly. This also reflects in their powers, because some Jokers have powers that would make them Aces if they weren't so hideously deformed.
- The wizards in Discworld are like this.
- Nynaeve in The Wheel of Time can only use her magic when she's angry. she gets better.
- In The Dresden Files, Harry's magic is partially based on emotion. On several occasions, he has gotten very angry and used it to amplify his fire magic. On another occasion, he has used a surge of lust induced by a White Court vampire to power a shield spell.
- He has also stated that sometimes color can become part of the spell, as seen in Proven Guilty when he builds the net to find the phobophages. There's black for vengeance, white for purity, etc. When building the net, he uses blue play-dough because of blue's connotations with defense. Plus, blue is cheaper. It is noted that the actual color isn't important- what helps is the mental associations the individual has with it. Because Harry was taught to use blue for defense, and has had past success that mentally associated blue and defense, it works best in that role for him.
- In Larry Niven's Known Space universe, this is how Gil "The Arm" Hamilton got his power and nickname. He had lost his right arm in an accident, but one day when he absent-mindedly tried to catch a dropped object with the missing arm, he manifested an "imaginary" psychic arm that works via telekinesis. One story notes that psychic abilities work only because the user believes in them.
- It should be mentioned that while Gil's arm can handle hazardous materials and reach through solid objects or live video feeds, it is otherwise limited to the same range as his flesh-and-blood arm (arm's reach), and only strong enough to lift a pound or two in Earth's gravity. People have asked Gil why he doesn't try hypnotherapy to correct these shortcomings; he points out that feeling like he has an arm ten feet long might interfere with his Willing Suspension of Disbelief and make his arm go away entirely.
- Three of the six main student wizards in Year of the Griffin have a particular quirk to their magic due to psychological issues:
- Lukin creates a pit of some kind whenever he tries to do anything with magic. Even his magefire appears in a little hole in his desk. This turns out to be symbolic of the emotional gap between his father and the rest of his family, which his father refuses to acknowledge.
- Olga used to be able to summon winds instead of monsters by talking to air elementals that no one else could see. Her talents got twisted up when she refused to let herself cry and stayed that way for years, but the minute she tears up the elementals are back to comfort her.
- Claudia's magic always seems to go wrong somehow, which she believes is due to a jinx. it's actually because she has a strong gift for translocation, and she hates travel because she feels like an outcast wherever she goes.
- Chuck's Intersect 2.0 flashes only when he is calm enough.
- In Haven, a person's Trouble first activates when they get stressed or upset.
- In Misfits, Curtis can only use his Mental Time Travel when he feels intense regret.
- The central gameplay mechanic of Super Princess Peach is activating one of four "Vibes", which are abilities based on four emotions. In Joy, she gets the ability to float. In Rage, she gets surrounded by fire and gets a Shockwave Stomp. In Gloom, she gets Ocular Gushers that spray Swiss Army Tears. In Calm, she heals herself.
- Zimmy from Gunnerkrigg Court has some kind of Psychic Power (her exact abilities are rather vague so far). She also has a mental disorder—she describes it like having static in her head. The worse the static gets, the less control she has to prevent her powers from acting up.
- El Goonish Shive: Grace has telekinesis just strong enough to "arm-wrestle". But when someone makes her explode (figuratively), something may explode (literally).
- In Brennus, some metahumans' powers grow in strength as they approach the mindset they had during their Traumatic Superpower Awakening.
- Presto from Dungeons & Dragons had this problem. No confidence in his abilities, so his magic worked sporadically, and rarely as intended.
- In one episode of Danny Phantom, he temporarily gains the ability to control the weather, but it's based on his emotions instead of consciously controlled.
- This also applies to his general ghost powers during the beginning when it was more sensitive to his growing emotions.
- In Teen Titans, Toonverse Starfire's powers are apparently triggered and/or powered by specific emotions, e.g., joy for flight, rage for Eye Beams etc. Naturally this little factoid first cropped up when she got bodyswapped with Raven, whose powers go haywire without tight emotional control. It comes up again later, when Starfire finds herself unable to fly because she's confused as to the status of her relationship with Robin.
- Rex's powers from Generator Rex require him to be focused and level headed when using them. If he loses his concentration, for instance if he becomes confused his powers will fail.
- Bending works this way in Avatar The Last Airbender. Aang has to adjust his mindset when he learns a new element, which becomes a serious problem when the happy-go-lucky hero has to learn to be steadfast and forceful to learn Earthbending. Zuko also loses most of the power behind his Firebending when he joins the good guys and loses the hatred in his heart. Luckily, he finds a secret society where he learns that Firebending is about passion, not anger.
- In the episode of Adventure Time, "Little Dude", The Ancient Sleeping Magi of Life Giving has life-giving powers that are dependent on his mood. When he thinks of his father, who it's implied never loved him, the objects he animates turn evil, but when he thinks of his mother, who loved him, the objects he animates turn good.
- Steven Universe While the Crystal Gems are all thousands of years old and have effortless usage of their powers, the titular Steven is handicapped by being half human, and by being only twelve years old. As such, his powers tend to work erratically. It is only when The Power of Love is invoked that he can call his powers at will with certainty.
- In The Amazing World of Gumball, Penny Fitzgerald turns out to be a shapeshifter whose form underneath her peanut shell is based on her self-image. She's rather self-conscious about it, which indirectly leads to her mimicking the way people describe her (or that she thinks they're describing her).