angel - so Coptic and Andreas. But A, B, C, Vulgate, and Syriac omit it.
upon - not as in Rev 16:2, Rev 16:3, “into.”
sun - Whereas by the fourth trumpet the sun is darkened (Rev 8:12) in a third part, here by the fourth vial the sun’s bright scorching power is intensified.
power was given unto him - rather, “unto it,” the sun.
men - Greek, “the men,” namely, those who had the mark of the beast (Rev 16:2).