When a Spell Trap Card, or monster effect, is activated, while you control a Number Xyz Monster: Negate the activation, and if you do, destroy that card. If a Number Xyz Monster(s) you control is destroyed by battle or card effect, while this card is in your GY: You can Set this card, but banish it when it leaves the field. You can only use 1 Numbers Protection effect per turn, and only once that turn.