This UberASM allows you to set up a combination of buttons that will hurt or kill Mario when pressed. You can set the logic to hurt/kill when any of the selected buttons are pressed, or when all of the selected buttons are pressed. If using the latter, keep in mind that some combinations may not be possible in practice due to controller/keyboard limitations. By default, it is set to kill Mario when left or right are pressed.
It is a fine code as is, but, being simple enough, some issues made me not accept it. The reason? Let's say I want to set Mario to be killed when, and only when, the player presses B + Right. Your code, as is, does not allow this setting, because if you set it to do so, the combination A + Right would kill Mario as well. The same can be said about X + Right versus Y + Right, for instance. A minor logic work can be done to fix this, thus enabling this code to be accepted.