Outer Entity Nyarla

The monster effect "①: When this card is Xyz Summoned: You can discard any number of cards; this card's Rank increases by the number of cards discarded" is a Trigger Effect. (When activating this effect, you discard any number of cards, 1 or more, as the cost.)

The monster effect "②: Once per turn, if this card has Xyz Material, you can target 1 monster in your Graveyard; detach all Xyz Materials from this card, and if you do, attach that monster to this card as Xyz Material. This card's Type and Attribute become the original Type and Attribute of the monster attached as Xyz Material by this effect" is an Ignition Effect. (This effect targets 1 monster in your Graveyard.)

Detaching Xyz Materials from "Outer Entity Nyarla" by its own effect is part of the effect resolution. It is not a cost.

The process of detaching Xyz Materials from "Outer Entity Nyarla," the process of attaching the targeted monster to this card as Xyz Material, and the process of this card's Type and Attribute becoming the same as that monster's are all treated as occurring simultaneously.