Antonyms of the phrase "more horror struck" can include "calm," "serene," "tranquil," "peaceful," "relaxed," "composed," and "undaunted." These words convey a sense of composure and serenity, implying that the individual is not overwhelmed or shaken by the situation at hand. Other antonyms may include "content," "happy," "pleased," "satisfied," and "blissful," indicating that the person is not experiencing any negative emotions or thoughts. These antonyms offer a contrasting view to the phrase "more horror struck" and can help to balance and enhance the overall tone and meaning of the piece of writing.