How to have a MUGEN Character behave like a Smash character?

[TaylortheToonFighter]

From times of approaching Ky-Shanxi's Smash Bros. MUGEN, I know begin to question on when creating a character, how can I have the character behave like a Smash character. It's not just the code based from the video on how to make the character into a Smash character, it was for how the character can actually behave more like a Smash character than a MUGEN character. Like Ky-Shanxi's Ness for example. When the character turns automatically, and does smash attacks, and such? How is that possible?