* "The erstwhile bustling marketplace now stood silent and deserted." (This sentence highlights a change in state, showing that the marketplace was once busy but is now quiet.)
* "The erstwhile champion was defeated by a young, up-and-coming challenger." (This sentence emphasizes a loss of status or power, showing that the champion was once dominant but is now defeated.)
* "The erstwhile friends had a falling out after a heated argument." (This sentence refers to a past relationship, highlighting the fact that the friends were once close but are now estranged.)
* "The erstwhile king, now a humble farmer, lived a quiet life in the countryside." (This sentence demonstrates a change in role, highlighting the fact that the king was once powerful but is now ordinary.)
Note: "Erstwhile" is often used to emphasize a change in state or status, and it can sometimes create a sense of nostalgia or irony.