Cease exist could be replaced by several antonyms that indicate the continuity of existence. Words like persist, endure, survive, flourish all indicate a state of being that is not discontinued. Another antonym for cease exist could be perpetual or everlasting, meaning that something is ongoing and not coming to an end. Similarly, terms like sustained, upheld, and maintained all indicate the continuation of existence. In contrast, words like stop, halt, discontinue, and end signify an interruption in the existence of something. Ultimately, the choice of antonyms will depend on the context in which the word is being used, and the meaning that the speaker wants to convey.