Aggressor (居合一閃 Iai Issen, lit. Quick Slash in the Japanese version, Affondo in the Italian version, Ofensiva in the Spanish version) is a Skill from Fire Emblem: Awakening and Fire Emblem Fates. It increases the user's attack rating when the user initiates the battle. It is learned by Dread Fighters.
Aggressor cannot be passed down as with all other DLC related skills. All male units in the game can learn the skill by reclassing into the Dread Fighter class via a Dread Scroll.
In Fates, the skill also cannot be bought from My Castle or the Logbook. As Dread Fighter is now a unisex class, all characters can learn the skill.
Aggressor's Japanese name Iai Issen comes from Iaido, a Japanese sword martial art that involves a quick drawing of a sword from its scabbard, slashing the opponent, then sheathing it in a smooth, fast, and controlled manner.