There are several synonyms for the phrase "are in the power of." Some additional phrases that can convey a similar meaning include "are at the mercy of," "are subject to," "are under the control of," and "are under the rule of." These phrases are often used to express the idea that someone or something is under the authority or domination of another entity. Whether discussing personal relationships or larger systems of governance, these phrases can be helpful in articulating power dynamics and the relationships between different actors. By using these words and phrases intentionally, communicators can clarify power structures and acknowledge the ways in which certain groups are privileged or disadvantaged.