A. Create a custom object that connects Cases to each other with two Case lookup fields and add a check box field to designate the parent Case.

B. Create a custom field for an ID number and assign the same number to all cases that need to be connected

C. Use Case Hierarchy to connect all Cases for the client to a parent case and click on View Hierarcht to see the connected Cases

D. Use Case Comments and paste the URL of the first Case opened for the client in each new Case related to them.