The Muscle Revenger is one of the Three Great Secret techniques passed down among the Kinniku family. Despite this, it has been mastered by Chojin who were not from the Kinniku clan, such as Phoenix, and even some actual members of the Kinniku clan have been shown as unable to use it, such as Mayumi and even Kinnikuman himself. There are two versions of this technique: Phoenix's version (the actual Muscle Revenger), and Kinniku Mariposa's version (a fake)
Mariposa's Muscle Revenger (called the Phony Muscle Revenger or the Reverse Muscle Revenger due to it being a reverse of the actual Muscle Revenger in image) is an incomplete, false version of the Muscle Revenger. In it, Mariposa jumps high into the air with his jumping ability and comes down on his opponent with a headbutt (thus resembling a vertical Muscle Millennium). The weakness of the false version was that it could easily be destroyed by distracting Mariposa, causing him to look away from his target. Kinniku Mayumi revealed that it was a fake when the technique was almost effortlessly destroyed.
Phoenix's version, the true Muscle Revenger, is a much more complicated technique than Mariposa's. Rather than simply jump into the air and come down on his opponent, Phoenix throws his enemy high into the air with a series of headbutts, and when that opponent comes down, he meets him with a much more powerful headbutt. Kinniku Suguru joked that Phoenix's version was an even more obvious fake than Mariposa's, as Phoenix made it look like he was the one being hit by the Muscle Revenger, to which Phoenix revealed that this was the true move, and the one they thought was the target in the image was actually the one performing the move.