RPCS3 Forums

After seeing that rpcs3 supports local multiplayer (windows only) if you use xinput controllers, I did a few tests to see if I was able to use 2 custom fighting sticks to battle with a friend.
Short answer: yes.
For this, follow these steps:

1. go to http://www.x360ce.com/ and download the 64bit version
   
2. unzip and launch. It will create a xinput1_3.dll file
   
3. here's the key point: rename the xinput1_3.dll in xinput1_4.dll
   
4. copy x360ce_x64.exe and xinput1_4.dll in the folder where you have the rpcs3 exe.
   
5. plug your custom controllers, launch x360ce_x64 and configure the buttons. This will create a x360ce.ini
   
6. close x360ce_x64 (it's just to help you create the correct ini file). Launch rpcs3 and enjoy your fighting game with your friends !
   

Tested on win10.