The phrase "are out for blood" is often used to describe intense aggression or a desire for revenge. However, there are several antonyms that can be used to convey a less hostile meaning. For example, "are at peace" implies a sense of calm and serenity, while "are forgiving" suggests a willingness to move past conflicts and offer mercy. "Are indifferent" implies a lack of emotion or interest in the situation, while "are understanding" suggests empathy and the willingness to see the other person's perspective. Ultimately, the antonym used will depend on the context and intended meaning of the conversation or situation.