You can Xyz Summon this card on "Tiras, Keeper of Genesis" after the Battle Phase in which it was left with just one Xyz Material. Since "Tiras" would lose his last Material anyway during the End Phase, this is a very good way to summon this card. Since it'd have only 1500 ATK, it's best to summon it that way to clear a defensive wall, such as "Scapegoat's" tokens.
If you have "Number 19: Freezadon" on the field when this card is summoned, it can use its Xyz Materials in replacement for this monster's, which will keep her power high and still be able to use her effect.
If this card has run out of Xyz Materials, "Numbers Overlay Boost" can give it two more materials straight from your hand. This is very useful if you run out during your opponent's turn, which would otherwise leave this card as easy prey.
"Number Wall" can protect this card from being destroyed, even if it runs out of Xyz Materials, keeping it safe until one replenishes "Frozen Lady Justice's" Xyz Materials.