How do I make a fighting game?

From OHRRPGCE-Wiki

You don't. The OHRRPGCE is not designed for making fighting games, it is designed for making RPG games. Although it is theoretically possible to make a fighting game in the OHRRPGCE using plotscripting, this would be extremely hard-- harder than making a fighting game from scratch in a programming language, so it would be silly to attempt it.

If you want to make a fighting game, you might want to consider a game maker designed specificly for fighting games, like Mugen