Could someone provide me an idea of what a Jian vs rapier fight would look like?

Rapier guy would be keeping his distance to maintain a reach advantage. Will use the point a lot. If i were using the rapier id would also throw in cuts to the jian wielder's hand as it lacks good hand protection

Jian guy would likely be trying to achieve a bind on the rapier to allow him to close distance rapidly. When jian guy gets the bind he will probably rush in with great aggression.

Have a look at the video here. Rapier vs sabre, not exactly the same as what you're looking for but displays some of the stuff i mentioned
https://youtu.be/NIdgIsEhd5E