The phrase "coming stage" typically refers to an upcoming phase or step in a process or event. Antonyms for this phrase could include terms such as "concluding stage," "final phase," "endgame," "culmination," or "completion." These words suggest an ending or conclusion to a process or event, rather than a beginning or next step. Other antonyms for "coming stage" might include descriptors like "past," "finished," "completed," "previous" or "concluded." These terms emphasize the idea that the stage or process in question has already occurred or been completed, rather than being something that is still to come.