"в целом "Undertale" не кажется мне слишком сосредоточенным на религиозных аллюзиях"
...имя Азриэля таки есть в словаре ангелов! Точнее, там нет имени "Asriel" - но есть "Asrael" и "Azrael".
"Asrael - an angel in a Cact opera of that name composed by Alberto Franchetti, with libretto by Fontana. Based on the old Flemish legend, Asrael falls in love with another angel called Nefta (female), loses her, and finally is reunited with her in Heaven. The opera had its first American performance in 1890 at the Metropolitan in New York".
"Azrael (Azrail, Ashriel, Azriel, Azaril, Gabriel, etc. - "whom God helps") - in Hebrew and Islamic lore, the angel of death, stationed in the 3rd Heaven. To the Moslems, Azrael is another form of Raphael. In their tradition, he has "70,000 feet and 4,000 wings, while his body is provided with as many eyes and tongues as there are men in the world." [Rf: Hastings, Encyclopaedia of Religion and Ethics IV, 617.] In Arabic tradition, Azrael is "forever writing in a large book and forever erasing what he writes; what he writes is the birth of a man, what he erases is the name of the man at death." When Michael, Gabriel, and Israfel failed to provide 7 handfuls of earth for the creation of Adam, the 4th angel on this mission, Azrael, succeeded; and because of this feat he was appointed to separate body from soul. [Cf: Murdad, the angelus mortis in ancient Persian lore.] Oriental legend has it that Azrael accomplishes his mission (i.e., bringing death first and separation afterward) by holding an apple from the Tree of Life to the nostril of the dying person. In Jewish mysticism, Azrael is the embodiment of evil. In The Book of Protection he is one of 3 holy angels (the other 2 being Gabriel and Michael) invoked in Syriac charms. He is the angel of death in Longfellow's poem "The Spanish Jew's Tale" and, in the popular edition of The Complete Poetical Works of Henry Wadsworth Longfellow, he is pictorially represented with King Solomon entertaining a "rajah of Hindostan"".
В чём-то это действительно подходит Азриэлю из "Undertale" - с его небывалыми способностями и очень двойственной ролью в повествовании. Хотя, конечно, имена ангелов в произведениях трактуются и используются максимально широко. Чего стоит Араил-Ариэль - диснеевская русалочка, дух-помощник у Шекспира и ангел, довёдший Аску до комы, в "Евангелионе".