The Shun goku
Satsu is the ultimate attack of the Shotokan style
in the Street fighter
series. This attack
was feared and sealed away due to its extreme and fatal power
One of the past masters of the Shotokahn school named Gouki, unsealed this power saying that they were fools for sealing it. But in reality, Gouki sealed his own fate when he discovered it wasn't an actual attack they sealed away. It actually a true demon, the demon possessed Gouki and gave him a demonic look and a horrible desire to fight and kill as many opponents before he dies.
The actual attack though is a type of hold, unblockable and can only be dodged or countered by hitting Gouki out of it. When the attack is successful, Gouki grabs the opponent and everything goes white. During this fifteen flares fly and the light disappears. The opponent is laying down on the ground next to Gouki, dead. Gouki stands with his back turned and the kanji symbol "ten" (which means heaven) glows on his back.
The attack is not a physically damaging attack, it kills you through your own sins. All of your past evil deeds come back to you and kill you. So if you are pure of heart, the attack cannot harm you at all.
Finally the shun Goku Satsu attack has many numerous nickanames as well-
"The Raging Demon"
"The Demon Rage"
"The Fire Cracker"