^ That, and sometimes its the amount of effects or the code. (Its could be my computer, but Evil Soul lags when using most of his moves. D;)
well maybe you had too much stuff on your computer.but generally, the more "stuff" you have in mugen means the more lag.depends on the machine though.
Maybe you have to much files on your computer? Or maybe MUGEN isn't for the computer you may have? Don't know.