Mugen Gettag Link
The beauty of Mugen is customization. To add more characters to your Gettag build:
Pro Tip: Gettag builds are notoriously picky. Only use characters labeled "Mugen 1.0" or "WinMugen+," and avoid "Mugen 1.1" characters unless you want an immediate crash. mugen gettag
In your data/select.def file, the entry must match the folder name, not necessarily the internal name. The beauty of Mugen is customization
Every character folder contains a .def file (e.g., Ryu.def). Open it with Notepad. Look for the line: Pro Tip: Gettag builds are notoriously picky
name = "Ryu"
That internal name is the true tag of the character.