Diagrams for 2 choosen systems

I need you to design it. I require some diagrams for 2 choosen systems. I will explain what my systems are and i require the diagrams that link to the systems. I am unaware of which diagrams i would need for the system so this is why when you message me, we will discuss what the system is. You will then have to decide which diagrams meet that system and create them using Microsoft Visio. Some diagram examples are: Use Case Diagrams, contect diagrams, sequence diagrams, class diagrams, state diagrams