The Shun Goku Satsu is a forbidden technique of the Shotokan style due to its tremendous and fatal power. The real power of the Raging Demon is based on the soul of the opponent because it kills through the sins of your enemy. If the opponent is an evil character, his fate is doomed but if he or she is pure of heart, the Raging Demon will have no effect. Until now, Gen is the only known survivor of the Shun Goku Satsu.
Although Akuma (aka Gouki) has mastered this technique, allowing a demonic possession over himself, several characters in the Street Fighter universe uses it as well like Ryu (evil Ryu) and Sakura (a parody).