Parallel
Revelation 20:1
Nestle 1904 Greek New Testament · Berean Standard Bible
Καὶ εἶδον ἄγγελον καταβαίνοντα ἐκ τοῦ οὐρανοῦ ἔχοντα τὴν κλεῖν τῆς ἀβύσσου καὶ ἅλυσιν μεγάλην ἐπὶ τὴν χεῖρα αὐτοῦ
Then I saw an angel coming down from heaven with the key to the Abyss, holding in his hand a great chain.