A mysterious figure pursuing the Abyss Order.

He wears jet-black attire, and his right arm has undergone a sinister transformation. The right half of his face is covered by a mask-like object.

Emotionless and taciturn, he rarely seeks interaction with others, leaving much of his nature a mystery. However, he harbors intense hostility toward the mysterious Abyss Order and works to thwart their schemes.

He is a survivor of Khaenri'ah, an ancient nation destroyed by the gods 500 years ago.

He was the final captain of the Khaenri'ah Royal Guard, known as the "Bough Keeper," but he failed to prevent his homeland's destruction. Furthermore, he was afflicted with the curse of immortality and forced to wander aimlessly, watching as the people he tried to protect transformed into the monsters of the Abyss.

He harbors deep resentment and distrust toward the gods who annihilated his country and the "Five Sinners," the high-ranking officials who abandoned it.

He warns others to "not believe in the gods" and to "not fall into the path of usurpation and atrocity." If the former refers to the gods and the latter to Khaenri'ah, it implies he views neither path as righteous and currently belongs to no faction.

Although he maintains a youthful appearance, the curse of immortality does not naturally include eternal youth; the body and mind are meant to slowly decay. Dainsleif himself muses that those cursed could not possibly maintain their sanity without "a certain something."

This is apparently due to a "ring" he was given, which allows him alone to reset his physical state as many times as needed.