Merrow dalla Scia Prismatica (Prismwake Merrow)
Merrow dalla Scia Prismatica 

Quando il Merrow dalla Scia Prismatica entra in gioco, un permanente bersaglio diventa di uno o più colori a tua scelta fino alla fine del turno.
Testo delle regole (Oracle, inglese)
When this creature enters, target permanent becomes the color or colors of your choice until end of turn.
"Vedere per credere" è un detto che i merrow sfruttano senza pietà nei loro affari con gli altri abitanti della Landa Tenebrosa.
Legalità
Chiarimenti sulle regole (in inglese)
2008-05-01
An effect that changes a permanent’s colors overwrites all its old colors unless it specifically says “in addition to its other colors.” For example, after Cerulean Wisps resolves, the affected creature will just be blue. It doesn’t matter what colors it used to be (even if, for example, it used to be blue and black).
2008-05-01
Changing a permanent’s color won’t change its text. If you turn Wilt-Leaf Liege blue, it will still affect green creatures and white creatures.
2008-05-01
Colorless is not a color.
2008-05-01
You can choose any single color or any combination of more than one color. You can’t choose colorless.
2008-05-01
This ability won’t make an artifact stop being an artifact. It’ll just be a colorful artifact.