So your protagonist needs a vice/flaw that they need to get over before they can see the truth by the end of your story. Pick one that best works in opposition to give the biggest arc possible.
Addiction – A state of physiological or psychological dependence on a potentially harmful drug
Adultery – voluntary sexual relations between a married person and somebody other than his or her spouse
Aggression – threatening behavior or actions
Alcoholism – dependence on alcohol consumption to an extent that adversely affects social and work-related functioning and produces withdrawal symptoms when intake is stopped or greatly reduced
Anger – a strong feeling of grievance and displeasure
Antagonism – hostility or hatred causing opposition and ill will
Arrogance – the act of feeling or showing self-importance and contempt or disregard for others
Avarice – an unreasonably strong desire to obtain and keep money
Bias – an unfair preference for or dislike of something
Bigotry – when somebody with strong opinions, especially on politics, religion, or ethnicity, who refuses to accept different views
Boastfulness – to refer immodestly to possessions or achievements
Bragging – to talk with excessive pride about an achievement or possession
Brutality – unrelentingly harsh and severe; extremely ruthless or cruel
Callousness – showing no concern that other people are or might be hurt or upset
Chauvinism – unreasoning, overenthusiastic, or aggressive loyalty to a particular gender, group, or cause
Cheating – to deceive or mislead somebody, especially for personal advantage
Conceit – a high opinion of your own qualities or abilities, especially one that is not justified
Condescension – behavior that implies that somebody is graciously lowering himself or herself to the level of people less important or intelligent
Corruption – dishonest exploitation of power for personal gain; extreme immorality or depravity
Covetousness – to have a strong desire to possess something that belongs to somebody else
Cowardice – an absence of courage
Crabbiness – a disposition to be ill-tempered; irritable in character
Crankiness – disagreeable and easily irritated or annoyed
Craziness – not showing good sense or practicality; one affected by a psychiatric disorder
Cruelty – deliberately and remorselessly causing pain or anguish; bringing about pain and distress
Cupidity – greed, especially for money or possessions
Decadence – a state of uninhibited immoral self-indulgence
Deceitfulness – intentionally misleading or fraudulent
Dementedness – completely unreasonable or lacking any sense of the consequences of actions taken; affected by the loss of intellectual functions
Depressive – to make somebody feel very sad or hopeless
Despairing – somebody that makes somebody else feel hopeless or exasperated; to feel there is no hope
Discourtesy – behavior or an action that is bad-mannered or impolite
Dishonesty – the use of lies or deceit, or the tendency to be deceitful
Disloyalty – a lack of loyalty to a person, vow, organization, or state
Disrespect – total contempt; to treat another with disregard
Doubt – to feel unconvinced or uncertain about something, or think that something is unlikely
Egoism – the practice of making personal welfare and interests a primary or sole concern, sometimes at the expense of others
Envy – the resentful or unhappy feeling of wanting somebody else’s success, good fortune, qualities, or possessions
Erratic – not predictable, regular, or consistent, especially in being likely to depart from expected standards at any time
Extremism – the holding of radical political or religious views or the taking of extreme actions on the basis of those views
Faithlessness – not believing in a religious faith; not to be trusted or relied on
Falseness – done with or having the intention of deceiving somebody; treacherous
Fanaticism – a holder of extreme or irrational enthusiasms or beliefs, especially in religion or politics
Fearfulness – nervous and easily frightened
Foolishness – showing, or resulting from, a lack of good sense or judgment
Fussiness – an irritable petulant feeling; unnecessary elaborateness in details
Glumness – quietly melancholic or miserable; gloomy ill-tempered
Gluttony – the act or practice of eating and drinking to excess; to do anything to the point of wastefulness
Greed – an overwhelming desire to have more of something such as money than is actually needed
Grouchiness – easily upset; angry; tending to complain; habitually bad-tempered and irritable person
Grumpiness – a fussy and eccentric disposition; bad-tempered or sullen
Hastiness – to do things or act in a hurry because of impetuosity or lack of time
Hatred – a feeling of intense hostility towards somebody or something
Haughtiness – behaving in a superior, condescending, or arrogant way
Heartlessness – having or showing no pity or kindness
Hedonism – a devotion, especially a self-indulgent one, to pleasure and happiness as a way of life
Hubris – excessive pride or arrogance
Hypocrite – somebody who pretends to have admirable principles, beliefs, or feelings but behaves otherwise
Hysteria – being impossible to hold back or control; to be afflicted with a state of extreme or exaggerated emotion such as excitement or panic, especially among large numbers of people
Idiocy – extreme lack of intelligence or foresight
Idleness – lazy and unwilling to work
Impatience – tending to be annoyed at being kept waiting or by being delayed; unable to tolerate a particular thing and easily annoyed by it
Impetuosity – to act on the spur of the moment, without considering the consequences
Inanity – meaninglessness or senselessness that suggests a lack of understanding or intelligence
Incompetence – lacking the skills, qualities, or ability to do something properly
Indolence – lethargic and not showing any interest or making any effort
Infidelity – unfaithfulness or disloyalty, especially to a sexual partner (Just like your mum)
Inflexibility – firmly established and impossible to change; adhering firmly and stubbornly to a viewpoint or principle
Injustice – unfair or unjust treatment of somebody, or an instance of this
Insanity – extreme foolishness, or an act that demonstrates such foolishness
Insolence – showing a malicious or aggressive lack of deference in speech or behavior; the quality of being boldly rude or disrespectful
Intemperance – having or showing a lack of self-control, especially in expressing feelings or satisfying physical desires
Irritability – easily annoyed or exasperated; extremely sensitive, especially to aggravation
Jealousy – to feel bitter and unhappy because of another’s advantages, possessions, or luck; to feel suspicious about a rival’s or competitor’s influence, especially in regard to a loved one
Languor – a pleasant feeling of weariness or weakness; listlessness and indifference in speech or behavior
Lavishness – given or produced in abundance or to excess
Laziness – unwilling to do any work or make an effort
Lethargy – a state of physical slowness and mental dullness resulting from tiredness, disease, or drugs
Lewdness – inclined to, characterized by, or inciting to lust or lechery; lascivious; obscene or indecent; salacious
Liar – someone who does not tell the truth
Licentiousness – pursuing desires aggressively and selfishly, unchecked by morality, especially in sexual matters
Lunacy – behavior that is regarded as unintelligent, inconsiderate, or misguided, or an example of it
Lust – the strong physical desire to have sex with somebody, usually without associated feelings of love or affection
Madness – rash or thoughtless behavior
Malice – the intention or desire to cause harm or pain to somebody; or to wish for someone to feel pain
Manipulative – using clever, devious ways to control or influence somebody or something
Melancholic – feeling or tending to feel a thoughtful or gentle sadness
Mercilessness – very harsh in the judgment and treatment of others; showing no compassion toward somebody or something; to continue at a high level of violence or unpleasantness without pause or relief
Moroseness – deep sadness; showing a brooding ill humor
Moodiness – having temperamental and changeable moods; tending to change mood unpredictably from cheerful to bad-tempered
Murderous – capable of, guilty of, or likely to commit murder
Narcissism – excessive self-admiration and self-centeredness; overestimation of one’s own appearance and abilities and an excessive need for admiration
Obduracy – stubbornly persistent in wrongdoing; not repentant
Obsessive – a particular action or thing occupies one’s thoughts constantly and exclusively; worrying compulsively about something or things generally
Obstinacy – stubbornly adhering to an opinion, purpose, or course, usually with implied unreasonableness
Offensiveness – causing anger, resentment, or moral outrage, sometimes to the point of physical repugnance
Perversion – deviating greatly from what is accepted as right, normal, or proper, relating specifically to sexual activities considered unusual or unacceptable
Petulance – ill-tempered or sulky in a peevish manner
Pitilessness – showing no mercy or compassion for the suffering of others
Pomposity – an excessive sense of self-importance, usually displayed through exaggerated seriousness or stateliness in speech and manner
Pride – a haughty attitude shown by somebody who believes, often unjustifiably, that he or she is better than others
Prejudice – an unfounded hatred, fear, or mistrust of a person or group, especially one of a particular religion, ethnicity, nationality, sexual preference, or social status
Preposterousness – going very much against what is thought to be sensible or reasonable
Pretentiousness – acting as though more important or special than is warranted, or appearing to have an unrealistically high self-image
Profligacy – extremely extravagant or wasteful
Promiscuity – behavior characterized by casual and indiscriminate sexual intercourse, often with many people
Rage – sudden and extreme anger
Rashness – acting with, resulting from, or characteristic of thoughtless, impetuous behavior
Recklessness – marked by a lack of thought about danger or other possible undesirable consequences
Resentfulness – annoyed or bitter about having been badly treated, or characterized by such a feeling of annoyance
Rowdiness – a rough and noisy person who often causes disturbances
Rudeness – disagreeable or discourteous in manner or action; offensive to accepted standards of decency
Ruthlessness – having or showing no pity or mercy
Secrecy – unwillingness to reveal information
Self-importance – an unrealistically high evaluation of your own importance or worth
Self-indulgence – lack of self-control in pursuing your own pleasure or satisfaction
Self-pity – the self-indulgent belief that your life is harder and sadder than everyone else’s
Selfishness – concerned with your own interests, needs, and wishes while ignoring those of others
Senselessness – apparently or really without purpose or meaning; demonstrating a lack of reason and intelligence
Short-Sightedness – doing or determining without taking the future into account
Sloth – a dislike of work or any kind of physical exertion
Snobbishness – displaying an offensively superior condescending manner
Spite – a malicious, usually small-minded desire to harm or humiliate somebody
Stingy – not generous in giving or spending money
Stubbornness – unreasonably and obstructively determined to persevere or prevail
Sulkiness – a sullen moody resentful disposition; in a bad mood and refusing to communicate because of resentment for a real or imagined grievance
Sullenness – dourly disposition; showing bad temper or hostility by a refusal to talk, behave sociably, or cooperate cheerfully
Tetchiness – oversensitive and easily upset or annoyed
Thieving – to steal something, or steal things
Thoughtlessness – showing a lack of planning or forethought; showing a lack of consideration for other people or for consequences
Treasonous – one willing to betray the allegiance owed by somebody to his or her own country
Triteness – one who overuses common phrases or conversation topics and consequently makes them lack in interest or originality
Tricky – likely to cheat or outwit somebody
Twisted – morally unacceptable; badly affected by unpleasant experiences or constant disappointment
Unfaithfulness – engaging in sexual relations with somebody other than a spouse or partner; untrue to commitments, duties, beliefs, or ideals
Unloving – not giving or reciprocating affection
Untrustworthiness – the trait of not deserving trust or confidence
Vainglory – excessive pride in or boastfulness about personal abilities or achievements
Vanity – excessive pride, especially in personal appearance
Vengeful – having or showing a strong desire for revenge
Voracity – unusually eager or enthusiastic about an activity
Wastefulness – using resources unwisely
Weakness – lack of strength, power, or determination
Wildness – overwhelmed by a strong emotion such as anger, grief, or desire; not tame; living or having lived in the wilderness
Wrath – strong anger, often with a desire for revenge
Zealousness – actively and unreservedly enthusiastic to the point of fervor