Purchase the Xbox 360 digital version of UMvC3 from the Xbox Marketplace (it still works via web browser). It will download and run on Xbox One and Xbox Series X with improved resolution and faster load times.
A: On original PS3/Xbox 360, the servers are shut down. On RPCS3 emulator, you can play online via RPCN (RPCS3’s custom network), but player population is low. Download Marvel vs. Capcom 3- Fate of Two Worlds
Absolutely. Despite the Ultimate version existing, the core gameplay loop of Marvel vs. Capcom 3 is timeless. Purchase the Xbox 360 digital version of UMvC3
If you specifically want the 2011 Fate of Two Worlds balance (where Sentinel had 1.3 million health and Tron Bonne’s launch attack was unblockable), you will need to buy a used PS3 disc or find a "vanilla mod" for the PC version of UMvC3. A: On original PS3/Xbox 360, the servers are shut down