This is a word that Gene Wolfe would use to describe some fantastical monster. You could tell someone that it was a minor part of the Book of the New Sun, and they’d believe you without hesitation. Alzabo, destrier,… alastor. Yep.
alastor, n.
Usually with capital initial. An avenging demon or god. More generally: any avenger of wrongs committed; an agent of retribution. Cf. NEMESIS n. 1.
Neh 