The phrase "be in power of" means to possess authority or control over something or someone. Synonyms for this phrase include hold sway over, have command of, exercise dominion over, wield power over, be at the helm of, reign over, govern, rule, preside over, and be in charge of. Each of these synonyms emphasizes the idea of being in a position of authority with the ability to make decisions and direct the actions of others. Whether in politics, business, or personal relationships, being in power of is a critical concept that encompasses the ability to influence and make an impact.