Once per long rest:
You point your finger and the creature that damaged you is momentarily surrounded by hellish flames. The creature must make a Dexterity saving throw. It takes 3d10 fire damage (2nd level) on a failed save or half as much damage on a successful one.
Starting at 2nd level, you can use your Channel Divinity to strike with supernatural accuracy. When you make an attack roll you can use your Channel Divinity to gain a +10 bonus to the roll. You make this choice after you see the roll but before the DM says whether the attack hits or misses.
As an action, you present your holy symbol and speak a prayer censuring the undead. Each undead that can see or hear you within 30 feet of you must make a Wisdom saving throw. If the creature fails its saving throw, it is turned for 1 minute or until it takes any damage. A turned creature must spend its turns trying to move as far away from you as it can and it can't willingly move to a space within 30 feet of you. It also can't take reactions. For its action, it can use only the Dash action or try to escape from an effect that prevents it from moving. If there's nowhere to move, the creature can use the Dodge action.