The phrase "most blood-and-thunder" is typically used to describe something that is sensational, dramatic, or exciting. Some antonyms that may be used to describe the opposite of "most blood-and-thunder" could include words like mundane, uneventful, boring, or dull. These words are used to describe situations or events that lack excitement, adventure, or thrilling experiences. Other possible antonyms for "most blood-and-thunder" could include terms like calm, peaceful, tranquil, or sedate. These words are used to describe situations or environments that are quiet, still, and devoid of excitement or drama.