Irresistible (5e Feat)
From D&D Wiki
Prerequisites: The ability to cast at least one spell.
You gain an innate magical aura causing you to become nearly irresistible
You gain proficiency in the Persuasion skill. If you are already proficient in this skill, you add double your proficiency bonus to checks you make with it.
When casting enchantment spells add your proficiency modifier to your spell save DC an additional time.
When using spell-like abilities that affect a target's mind, add your proficiency modifer to either your roll or to the DC of the effect