Necrozma, Dawn Wings

Flying, Lifelink, Partner with Necrozma
Whenever Necrozma, Dawn Wings attacks, each
player mills four cards, for each land milled this
way, create a token colorless Prism artifact with
"{t}: Add one of any color to your mana pool".
{w}{w}{w}{u}{u}{u}{b}{b}{b}, Sacrifice 10 Prisms:
Transform Necrozma, Dawn Wings.