Corpse Thrust, called Corpse Hit (骸打ち mukurouchi) in Japan, is a move introduced in Tekken Tag Tournament for Jin Kazama. He has retained this move, despite changing his fighting style. Devil Jin can also use this move since Tekken 5 and onwards.
When to use
This move is only of use for knocking the opponent back or taking advantage of an opponent who is off guard. It isn't the best choice for wakeup games, and is near impossible to use in a good juggle without wall splats. On block, the opponent will need to react quickly to counterattack, so Corpse Thrust is quite powerful in mid to lower level play.
In Tekken 5 and Dark Resurrection, this move can be used as a tech trap at the wall. This is done after executing a wall combo with Jin/Devil Jin which ends in the Demon Lift Kicks. If the opponent techrolls to Jin/Devil Jin's left, take a sidestep right and execute Corpse Thrust. If done correctly, it will hit the opponent's side, giving a violent knockdown and allowing a free hit.
On a side note, the computer has been particularly susceptible to this move since its beginning in Tekken Tag Tournament.