The phrase "most enemy" can be rephrased in a number of ways to convey a similar meaning. One option is to use the phrase "greatest foe," which suggests an adversary who poses a significant threat or challenge. Another synonym for "most enemy" is "arch-nemesis," which implies a long-standing and intense rivalry. "Nemesis" alone can also be used to describe a persistent and formidable enemy. Other possible synonyms for "most enemy" include "adversary," "antagonist," or "opponent," depending on the context and nature of the relationship between the parties involved. Ultimately, the choice of synonym will depend on the desired tone and level of emphasis in the message being conveyed.