A.T. Robertson Commentary Revelation 13:15

"And it was given [unto him] to give breath to it, [even] to the image to the breast, that the image of the beast should both speak, and cause that as many as should not worship the image of the beast should be killed." — Revelation 13:15 (ASV)

To give breath to it (δουνα πνευμα αυτη). This second beast, probably a system like the first (not a mere person), was endowed with the power to work magical tricks, as was true of Simon Magus and Apollonius of Tyana and many workers of legerdemain since. Πνευμα here has its original meaning of breath or wind like πνευμα ζωης (breath of life) in 11:11.

Even to the image (τη εικον). No "even" in the Greek, just apposition with αυτη (her).

That should both speak and cause (ινα κα λαληση κα ποιηση). Final clause with ινα and the first aorist active subjunctive of λαλεω and ποιεω. Ventriloquism like that in Ac 16:16.

That should be killed (ινα αποκτανθωσιν). Sub-final clause with ινα and the first aorist passive subjunctive of αποκτεινω, after ποιηση, as in verse 12 (future indicative).

As many as should not worship (οσο εαν μη προσκυνησωσιν). Indefinite relative clause with modal εαν (= αν) and the first aorist active subjunctive of προσκυνεω with the accusative την εικονα (some MSS. the dative). Note the triple use of "the image of the beast" in this sentence. "That refusal to worship the image of the emperor carried with it capital punishment in Trajan's time is clear from Pliny's letter to Trajan (X. 96)" (Charles).