The phrase "begged for mercy" denotes pleading or imploring for forgiveness, help, or respite. Antonyms of this phrase could include standing firm, refusing to yield, rejecting aid, or resisting assistance. Some other antonyms might include insisting on justice, seeking vengeance or retribution, protesting one's innocence, or appearing unrepentant. In some cases, the opposite of begging for mercy might be to grant it, to show compassion or leniency, or to offer forgiveness freely without any need for supplication. Ultimately, the antonyms of "begged for mercy" demonstrate the range of responses that can be given in the face of adversity or wrongdoing.