This plugin changes the battle formulas used by the engine to match the ones used in the Fire Emblem games for the Game Boy Advance.
To use it, you just need to drag this folder into the Plugin folder of your project.
You can modify some things by modifying the formula-settings.js file. You don't need programming knowledge to use that file. In there, you will find two variables. These variables are already set up in the same way as the FE GBA games, but you can change them if you want to have some difference from those games.
There is also the experience calculations, which are handled by the file exp-formula.js. If you don't want to use those formulas, remove that file from your project.