Numbers Protection
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.