Original Saver, Zero

:When this unit attacks from or is rode upon, [ 1 & 1], draw a card, choose one of your opponent's units, and increase or decrease its to 0 until end of turn. (Its at that time becomes 0) :When this unit is attacked, [discard a grade 3 from your hand], and increase or decrease that attacking unit's to 0 until end of that battle. (Its at that time becomes 0)