Being superior or dominating is a trait that many people aspire to. Hence, finding synonyms for the phrase "be supreme" can be essential in making written communication more robust and diverse. Some words that can be used as substitutes for "be supreme" include "reign supreme," "be in command," "dominate," "rule," "control," "govern," "prevail," "triumph," "excel," "outstrip," "outrank," "outdo," "outclass," "outmatch," "surpass," and "overshadow." Using these alternatives will help add variety to written communication, making it richer and more engaging for the readers.