Glimmer

It's far easier to conceal by revealing than to reveal by concealing.
You flick a coin into the air and make it sparkle with shimmering light, drawing the attention of all creatures within 30 feet of you. Each creature must make a Wisdom saving throw. A creature that is in combat has advantage on this saving throw. If a creature fails, it suffers disadvantage on ability checks until the start of your next turn.