nemesis — OET

nemesis

noun

1 this could prove to be the bank's nemesis:

downfall, undoing, ruin, ruination, destruction, Waterloo.

2 will Harry Potter finally defeat his nemesis, Voldemort?:

arch-enemy, arch-rival, enemy, rival, foe, adversary, opponent, antagonist, combatant, challenger.

3 the nemesis that his crime deserved:

retribution, vengeance, retributive justice, punishment, just deserts;

fate, destiny.

nemesis Oxford Dictionary of English