Mercy

Through study and experience, you've learned that some undead are intelligent and just wish to rest in piece and as such you've dedicated yourself to giving them mercy.

Once per long rest when engaged in combat with an undead creature with an intelligence score of 10 or higher, you may attempt a Persuasion check (DC = 8 + The Creature's Challenge Rating + The Creatures wisdom Modifier). If you succeed, The creature stops being hostile towards you and your allies, allowing you to lay it to rest, with all subsequent attacks being treated as Critical Hits so long as they meet the Armor Class to hit.