Answer:
I don't have any context on how these words are being used, but I can conclude that the speaker chose these words because they help portray the characters determintation during a dilemma.
Step-by-step explanation:
Vow
VERB
vowed (past tense) · vowed (past participle)
solemnly promise to do a specified thing.
Settle
VERB
settled (past tense) · settled (past participle)
resolve or reach an agreement about (an argument or problem).
Avenge
VERB
avenged (past tense) · avenged (past participle)
inflict harm in return for (an injury or wrong done to oneself or another).
Impunity
NOUN
exemption from punishment or freedom from the injurious consequences of an action.