"Art mercy of" is a phrase that can be interpreted in various ways. However, some synonyms for it could be "subject to the will of," "at the mercy of," or "in the hands of." These synonyms imply vulnerability or dependence on a higher power, authority, or circumstance. One could say that someone is "at the mercy of the weather" or "subject to the will of their superiors." It can also be used in situations where one's fate is uncertain, and they have no control over the outcome. In any case, the phrase "art mercy of" conveys a sense of powerlessness, which can be both daunting and humbling.