A taciturn Grim Angel. Dispatched with Ecthel to actuate the Retribution, known as "The Solitary Grim Angel". He is in the position of sempai to Ecthel, but after a certain incident, the two are separated. His Diviner is the flame lance "Lorelei".
He has unusually few appearances in the audio dramas, but he does show up in "Riviera Private School", in which he's the Student Council president.
Rose always speaks to him very respectfully, but he never calls her by name, addressing her as "Familiar" instead.
His voice actor is Masakazu Morita. His first-person pronoun is "Ore" (俺).
Ledah's Angel Code is "#1487 Caldyna=L.Rozwelli". It is unknown what the code's meaning is. Incidentally, in one of the other DHE games, "1487" was a very special year, but there's probably no significant connection.
CAUTION: There are spoilers past this point!
In exchange for his Diviner, Ledah lost his own emotions. Ordinarily, he does not discuss this.
Like Malice, Ledah understands the true form of the Retribution; however, he does not know the true reason for its actuation. When he realizes that Hector of the Seven Magi intends to use the power of the Sprite of Death in order to fulfill his ambition of becoming a god, he orders Ecthel to stop Hector.
After this, he loses his life shielding Ecthel from Malice's attack.
He should have lost his emotions, but mysteriously, the way he speaks to other people still changes depending on his mood. Usually he calls Ecthel "omae" (お前), but when he's irritated he switches to calling Ecthel "kisama" (貴様).
Essentially, this may indicate that Ledah still retains some capacity to feel emotion, but not to the degree that he is aware of it himself.