Apollyon- Book 2 of "The One Who Never Speaks" series

"whose name in Hebrew is Abaddon, The Angel of Death." (Ἀβαδδὼν), and then translated ("which in Greek means the Destroyer" (Ἀπολλύων, Apollyon))."

de·stroy
dəˈstroi/Submit
verb
put an end to the existence of (something) by damaging or attacking it.

death
deTH/Submit
noun
the action or fact of dying or being killed; the end of the life of a person or organism.