The antonyms for the word "most undestroyed" would be terms that convey destruction or damage. Some possible antonyms include "decimated," "devastated," "obliterated," "ruined," "wrecked," "demolished," or "annihilated." These words imply a state of destruction, dismantlement, or complete loss, representing the opposite of "most undestroyed." They suggest a condition of brokenness or destruction, where almost nothing has been left intact or functional. On the other hand, "most undestroyed" implies a state of preservation, resilience, or resistance against destructive forces, highlighting the overall health and soundness of the entity in question.