The idea of MvC3 on PC is glorious. The reality of downloading it is a buggy, illegal, performance-heavy headache. Don't waste your weekend.
Disclaimer: Marvel vs. Capcom 3 (including Ultimate MvC3) was never officially released for PC by Capcom. This review covers the "gray area" method of obtaining the PlayStation 3 or Xbox 360 version via emulation (RPCS3 or Xenia). There is no legitimate "download and play" option on PC as of this writing. Download Marvel Vs Capcom 3 Pc