Power Punch, named Shattering Fist (崩拳/Hō Ken) in Japan, is a move usable by Heihachi Mishima, Paul Phoenix, Wang Jinrei and Prototype Jack. During the course of the Tekken series the name of the technique has changed for each of the characters in the US and EU versions (e.g. Paul Phoenix: Phoenix Smasher), even though the name has always remained the same in the Japanese version.
This move is known by fans as the Deathfist. The only exception is when Heihachi started performing the move with an open hand instead of a fist in Tekken 4, at which point it was renamed Iron Hand in the US and EU and Vajra's Spear Palm (金剛槍掌 kongousoushou) in Japan. However, other than using an open hand, the command and execution of the move remained exactly the same. As a standalone move, it is also known as the Phoenix Smasher when used by Paul, and when used by Heihachi or Wang, it is also known as the Heavy Power Punch.
While Heihachi and Paul can perform this move after a Hammer Punch, Wang Jinrei, due to the lack of the Hammer Punch being in his movelist, can only perform it as an independent move. Prototype Jack can only perform a Power Punch as a chain combo, directly following a Hammer Punch.