Harrowing Swarm

Manifest dread. Then each face-down creature you control gains "This permanent costs {2} less to turn face up" and "When this permanent is turned face up, if it's a creature, put a +1/+1 counter on it."

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6okmh1exujpb1hvowf26jp.