Ulistrum's Magic Mirror

"Why would you hurt yourself with your own sword?" - Ulistrum

You summon a mirror that duplicates the target creature's attack and sends it back at it. The attacking creature takes half of the triggering damage as force damage and must succeed on a Strength saving throw, equal to your spell save DC, or be pushed 15 feet away from you and knocked Prone. Large creatures have advantage on this saving throw. Huge and bigger creatures automatically succeed this saving throw.

You still take the damage from the attack as normal. This only reflects the damage of a single attack, even if the attacker has multi-attack.