Sentouki Eagle Booster / Brandish Mecha Eagle Booster
Spell Quick-Play
(1) If you control no monsters in your Main Monster Zone: Target 1 face-up monster on the field; until the end of this turn, that target is unaffected by card effects, except its own, also if there are 3 or more Spell Cards in your GY, it cannot be destroyed by battle until the end of this turn.