Ego Trip

This spell has two durations. The first one is how long the spell's effect last, and the second one is how long the downside lasts. 

You lace your complimentary words with magical enchantments that give the target a massive ego boost. Choose a creature within range. They have advantage on all Charisma ability checks (not saving throws) for the first duration. After the first duration ends, more magic energy is sapped from them than the original spell requires. During the second duration (base time of one hour), the target has disadvantage on all Charisma ability checks.