The phrase "rent asunder" is commonly used to describe the act of tearing or ripping something apart. However, there are numerous synonyms that can be used to convey a similar meaning. Some examples of synonyms for "rent asunder" include split, cleaved, severed, torn, ripped, and shredded. These words all suggest a forceful breaking or separation of something. Additionally, phrases such as "torn in two" or "split as if by lightning" can be used to illustrate the suddenness and violence of the action. By using these synonyms, writers can add variety and depth to their descriptions of destruction and devastation.