Complex sentence: Even though many styles/style organizations like these have appeared during the last decade, there are no common set of rules or unifying sport organization... or even a common name/terminology for this type of karate competition rules.
Split into simpler sentences: Even though many styles/style organizations like these have appeared during the last decade, there are no common set of rules or unifying sport organization. Or even a common name/terminology for this type of karate competition rules.