Urza, Powerstone Prodigy

Vigilance
{1}, {T}: Draw a card, then discard a card.
Whenever you discard one or more artifact cards, create a tapped Powerstone token. This ability triggers only once each turn. (The token is an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

警戒
{1}，{T}：抓一张牌，然后弃一张牌。
每当你弃一张或数张神器牌时，派出一个已横置的魔力石衍生物。此异能每回合只会触发一次。（该衍生物是具有「{T}：加{C}。此法术力不能用来施放非神器咒语」的神器。）