Process Definition for Changing Status when Tasks are Completed

I'm trying to figure out how to make a process definition keep actively checking whether or not a task is complete. Once two tasks are both complete, I want the Case status to change. Right now, this sequence is executing all at once and not continuing to check when the tasks are complete. What can I do to achieve this or do I need to do something completely different?

Also, I'm trying to have the entire process terminated if the Case status changes to a specific variable. However, I'm encountering the same problem where the process is executing all at once and not continuing to check for a variable change. Thanks for any help or insight!