Photon Cloud is useful. But there is no tutorials of FPS game.
Therefore I made the FPS sample game with Photon Cloud.  
If you want to make your own FPS game , you can use this sample project for free.

steps;

1.Download "raytest" project

2.go to the directry "Assets" to open the file "level1" to the open Unity project.

3.If you don't have photon cloud account, goto https://cloud.exitgames.com/ and sign up.

4.Go to your photon cloud account and get "Application ID"

5.Go to unity project that you opened.  Open set up dialog by menubar "Window - Photon Unity Networking"

6.Push setting button, paste your Application ID, save it. (notice;Already inputed Id, it cant use)

7.Let's Play!

You can edit the project and publish for free.
If you have questions please ask me "edofrank.info[at]gmail.com"