Visage of Undeath

Using the blood of a dead man, you leave a blood-mark rune on the forehead of one creature.
For the next hour, the target is considered to be undead in addition to its other creature types.
If this effect is used on yourself, for the duration of the enchantment,  you also have advantage on any Charisma Ability Checks made against an undead creature.

"Sure, he may not be dead. But he's toeing the line."