Death Blow

Death Blow is a skill in the Fire Emblem series that was introduced in Fire Emblem Fates. It boosts critical rate when the user triggers a battle. There is a skill in Fire Emblem Echoes: Shadows of Valentia that works very differently.

Fire Emblem Fates
When the user starts the battle, he gains +20 in their critical hit rate. It works well with high critical weapons and skills that boost damage like Rend Heaven.

Fire Emblem Heroes
Since the game lacks a critical stat, Death Blow raises the Attack stat of the user when they initiate a fight. It increases the Attack more with the later versions. Death Blow 1 or the other relevant Blow skill is necessary to learn Swift Sparrow, Sturdy Blow or Mirror Strike.
 * Death Blow 1 - Cost 50 SP. Gives Attack +2 during combat when initiating the attack
 * Death Blow 2 - Cost 100 SP. Gives Attack +4 during combat when initiating the attack
 * Death Blow 3 - Cost 200 SP. Gives Attack +6 during combat when initiating the attack

Shadows of Valentia
Death Blow in Shadows of Valentia is the signature weapon skill of the Ilwoon. When the skill is used, it deals lots of damage effective against armored units at the cost of 4 HP. It takes 20 SP to learn.

Fire Emblem Fates
This skill is learned at level 5 by Oni Chieftains.

Fire Emblem Heroes
These characters have the skill naturally with the rarity they learn the 3rd level at unless they are only a 5 star
 * Alfonse - 4 stars
 * Delthea
 * Effie - 5 stars
 * Elincia
 * Klein - 4 stars
 * Hawkeye - 5 stars
 * Ursula - 5 stars
 * Roy (Love Abounds)
 * Siegbert
 * Eirika (Sacred Memories) - Only Death Blow 1
 * Katarina - Only Death Blow 1
 * Lyn (Brave Heroes) - Only Death Blow 1