“A mighty but cursed axe known to harm its user.”
—In-game description, Shadow Dragon and New Mystery of the Emblem
The Devil Axe (デビルアクス Debiru akusu) is a special Axe that appears across the Fire Emblem Series, beginning from the Archanea Series. This axe has the ability to to randomly deflect damage back to its wielder when it is used, the frequency of which depends on the Luck of its user. This makes the axe a risky weapon: while it is able to inflict enormous amounts of damage with a single strike, any backfires are similarly enormous.
In most games, the trigger rate of the Devil Axe's ability is [31-Luck]%. Exceptions to this rule exist in Thracia 776 and The Binding Blade, where the backfire rates are [21-Luck]% and [21-Level]% respectively. This ability can also be triggered when the axe is used to damage destructible map features like snags.
The The Blazing Blade and The Sacred Stones iterations of the Devil Axe award a very high amount of Weapon Experience per use, meaning that a unit could raise their axe Weapon Rank by a large amount in only a few uses. This is particularly useful for Paladins (The Blazing Blade) and Great Knights (The Sacred Stones), as it allows them to greatly accelerate their weapon ranks in Axes and more time to build up their ranks in Swords and Lances to solidify their control over the Weapon triangle.