The phrase "hast qualms" implies the sense of hesitation or doubt regarding a decision or action. Antonyms, on the other hand, are words with opposite meanings. Some possible antonyms to "hast qualms" could be "resolute," "confident," "decisive," or "unwavering." These words convey a sense of certainty, determination, and courage in taking action without any doubts or apprehensions. Using these antonyms could indicate someone who is willing to take risks, follow their instincts, and make bold decisions. Therefore, using powerful antonyms for "hast qualms" can give a sense of strength and conviction to a communication.