There are several options for synonyms for the phrase "one at the control." Some possible choices include a conductor, a pilot, a driver, a captain, a navigator, a controller, or a commander. These terms all refer to someone who is responsible for guiding or managing a particular process or activity. Depending on the context, some of these words may be more appropriate than others - for example, "conductor" tends to be used in reference to musical performances, while "pilot" typically applies to aviation or aeronautics. However, all of these synonyms convey the idea of someone who is in charge or in control of a given situation.