nemesis
Agent of downfall
A nemesis is an opponent or rival who persistently frustrates or defeats you—someone you can't seem to beat or escape: He's been my nemesis since high school.
The word implies a long-standing, almost fated antagonism.
More broadly, nemesis can mean any source of downfall or ruin: Hubris was his nemesis. (Capitalized Nemesis is the Greek goddess of retribution.)
Enemy in conflict
- opponentOne who contends against
- foeHostile opponent
- enemyHostile opposing party
- archenemyPrincipal antagonist
challenger · competitor · contender · antagonist · sworn enemy · combatant · threat · bête noire
Complete destruction or collapse
- defeatVictory over another
- undoingCause of destruction
- destructionAct of completely ruining
- collapseSudden structural failure
demise · failure · overthrow · doom · unraveling · catastrophe · humiliation · disintegration
Retaliation for injury
- paybackRetaliation for wrongs
- retaliationPunitive response to injury
- justiceFair treatment under law
- reckoningSettlement of accounts
punishment · karma · reprisal · avenger · comeuppance · poetic justice · just deserts · day of reckoning
Certain to occur
- inescapableImpossible to avoid
- unavoidableImpossible to prevent
- destinyPredetermined course of events
- doomUnavoidable grim fate
predestined · impending · looming · unrelenting · inexorable · pursuing · haunting · shadow
adversary
Enemy in conflict
archenemy · challenger · competitor · contender · antagonist · sworn enemy · combatant · threat · bête noire · foil
ruin
Complete destruction or collapse
- defeatVictory over another
- undoingCause of destruction
- destructionAct of completely ruining
collapse · demise · failure · overthrow · doom · unraveling · catastrophe · humiliation · disintegration · bane
vengeance
Retaliation for injury
- paybackRetaliation for wrongs
- retaliationPunitive response to injury
- justiceFair treatment under law
reckoning · punishment · karma · reprisal · avenger · comeuppance · poetic justice · just deserts · day of reckoning · eye for an eye
inevitable
Certain to occur
- inescapableImpossible to avoid
- unavoidableImpossible to prevent
- destinyPredetermined course of events
doom · predestined · impending · looming · unrelenting · inexorable · pursuing · haunting · shadow · curse
- Mythological WordsAchilles heel, Adonis, aegis, ambrosia, Apollo
- mythsmyth, legend, fable, fairy tale, folk tale
- rivalsrival, opponent, adversary, competitor, foe
- villainsvillain, antagonists, Darth Vader, evil characters, Joker
- Tropeschosen one, hero's journey, red herring, deus ex machina, damsel in distress
- dramaturgydramaturgy, dramaturg, dramatic structure, dramatic technique, dramatic form
- arch nemesisPrincipal long-term antagonist