Channel Divinity: Divine Flicker

As an action, you may emit a spark of divine power and choose between healing or harm. If you choose healing, when you activate this Channel Divinity and again at the beginning of your next turn, you and creatures of your choice within 10 feet of you regain hit points equal to half your cleric level, rounded down. If you choose harm, when you activate this Channel Divinity and again at the beginning of your next turn, hostile creatures within 10 feet of you must succeed on a Constitution saving throw against your spell save DC or take radiant or necrotic damage equal to half your cleric level, rounded down.