Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
The fifth angel sounds; and one who should have been by position the instrument of light and governmental order over the earth was seen as having lost his place; and the power to let loose the full darkening influence of Satan was given him. He opened the bottomless pit the place where evil is shut up and chained; not where it is punished, that is, the lake of fire. Supreme authority, and all heavenly light over the earth, and healthful influence of order, were darkened and made to cease by the evil Satanic influence which was let loose. Nor was this all: direct instruments of Satanic power came out of this evil influence in numbers; crowds of moral locusts with the sting of false doctrine in their tail. But it was not to destroy temporal prosperity on the earth, but to torment the ungodly Jews; not to kill, but to harass and vex them. This was to continue five months; for it is not the final judgment. The torment was worse than death pain and anguish of heart. But they had the semblance of military imperial power, crowned, and with masculine energy, to those that met them; but they were, if seen behind and the secret disclosed, subject and weak: their faces were as the faces of men, their hair as the hair of women. But they were armed in a steeled conscience. They were the direct instruments of the power of Satan, and under his orders. The angel of the bottomless pit he who rules the depths of Satan's wiles, as the ruler of the power of darkness led them. We are too unbelieving as to the direct influence of Satan in darkening men's minds when permitted, when men are given up to his darkening influence. Cruel harassing torments, worse than death, with darkening of their minds, become the portion of the once beloved people. One woe was past.
The sixth angel sounds. The woe which follows is much more human and providential. It is directed against the inhabitants of the Latin Empire. The instruments of it are let loose from beyond Euphrates a countless crowd of horsemen. But they were not simply such. Their consciences and their words, both were in the power of Satan, but in judgment from God. But it now killed men. Their mouths belched forth the power of Satan, and their influence in doctrine was Satanic: with both they did hurt. I do not believe this death here is mere temporal death (there may be such), but, I suspect, making apostates. The rest, who did not thus fall, did not repent of their idolatry and misdeeds.