Parallel
Revelation 9:11
Robinson-Pierpont Byzantine Textform · Berean Standard Bible
Ἔχουσαι βασιλέα ἐπ’ αὐτῶν ἄγγελον τῆς ἀβύσσου· ὄνομα αὐτῷ Ἑβραϊστὶ Ἀββαδών, ἐν δὲ τῇ Ἑλληνικῇ ὄνομα ἔχει Ἀπολλύων.
They were ruled by a king, the angel of the Abyss. His name in Hebrew is Abaddon, and in Greek it is Apollyon (note: Apollyon means Destroyer.).