Complex sentence: Extreme Martial Arts, often referred to as XMA, is not a martial art in itself, it is a combination of made up martial arts kata or forms, acrobatics, and gymnastics, with an emphasis on showmanship.
Split into simpler sentences: Extreme Martial Arts, often referred to as XMA, is not a martial art! It is a combination of made up forms, acrobatics, and gymnastics, with an emphasis on showmanship.