Download application called Wine
https://wiki.winehq.org/MacOS
> install it (when installing try to make the prefix directory or folder in desktop for easy access, This will be your C:// drive or Windows folder that deals with windows applications)
Download Mir installer
https://www.thelegendofmir.com/Legend_of_Mir2_Install.exe
> install it, This will install the mir game and its patcher in program files in your prefix folder
> wait for the the game to download. if it doesnt happen then go to the mir directory and run Mir.exe with wine.. this will install all files and patches
> Enjoy the game
> in the future when there is an update then you need to go to your mir folder and click on mir.exe, which is the patcher.. once recent updates are downloaded then you can click on Mir2.exe to play... or you can always just use Mir.exe which is also fine.
Goood luck
You can also use another application called Playonmac or install Virtual machine like VMware.. but for me atm Wine is the best option.