Duma's Gift is an enemy-exclusive skill in Fire Emblem Echoes: Shadows of Valentia.
Duma's Gift is exclusively used by Jedah during the final battle of Echoes. This skill causes any ally character who attacks Jedah to have all of their attacks negated for that round. However, Jedah can only negate the first three attacks initiated on him. The fourth attack cannot be negated, allowing the player to attack and wound him in that instance.
For example, having Tobin, Gray, Kliff, and Alm initiate an attack on him in that order, Tobin, Gray, and Kliff's attacks are negated but Alm's will go through. Duma's Gift negates the entire round of attack, hence if a character could double Jedah, Jedah only loses one round of use. In the case of the fourth attack on him, he cannot negate the second attack either.