Jihad

As this enchantment enters, choose a color and an opponent. White creatures get +2/+1 as long as the chosen player controls a nontoken permanent of the chosen color. When the chosen player controls no nontoken permanents of the chosen color, sacrifice this enchantment.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6oki2beuxjpb1h8fadk4yg.