The word "be the king" is a commonly used phrase that refers to someone who holds a dominant or authoritative position. However, there are several synonyms that can be used in place of this phrase, such as "reign supreme," "rule the roost," "wear the crown," "dominate," "hold sway," "be in command," "control the show," "be the top dog," "lead the pack," or "occupy the throne." Each of these synonyms conveys a similar sense of power and control, but adds a unique nuance to the meaning of the phrase. By using these synonyms, writers and speakers can add variety and interest to their language, while still conveying the intended message.