Aggressor (Quick Slash in the Japanese version) is a Skill from Fire Emblem: Awakening. It increases the user's attack rating by 10 when the user initiates the battle. It is learned by Dread Fighters at Level 15. It cannot be passed down to the children characters.
As with all skills obtained through downloadable content, this cannot be passed on to any children characters from the parents. (However, if the character is eligible to change into that class they can obtain the skill anyway.)