If you find a "Portable Overwatch" that claims to work offline or includes "all skins unlocked" without connecting to the internet, it is likely How to Create Your Own Portable Overwatch
The game files must be updated to the latest version to connect to Blizzard’s servers. overwatch repack portable
You can move your game folder from your home PC to a laptop or a friend’s house without waiting for a 30GB+ download. If you find a "Portable Overwatch" that claims
Copy the entire _retail_ folder to your USB 3.0 or external SSD. overwatch repack portable