For he will appoint princes over them from among the demons. And he will no longer seem to be pious, but altogether and in all things he will be harsh, severe, passionate, wrathful, terrible, inconstant, dread, morose, hateful, abominable, savage, vengeful, iniquitous. And, bent on casting the whole race of men into the pit of perdition, he will multiply false signs. For when all the people greet him with their acclamations at his displays, he will shout with a strong voice, so that the place shall be shaken in which the multitudes stand by him: “You peoples, and tribes, and nations, acquaint yourselves with my mighty authority and power, and the strength of my kingdom.
What prince is there so great as I am? What great God is there but I? Who will stand up against my authority?”Under the eye of the spectators he will remove mountains from their places, he will walk on the sea with dry feet, he will bring down fire from heaven, he will turn the day into darkness and the night into day, he will turn the sun about wheresoever he pleases; and, in short, in presence of those who behold him, he will show all the elements of earth and sea to be subject to him in the power of his specious manifestation.
For if, while as yet he does not exhibit himself as the son of perdition, he raises and excites against us open war even to battles and slaughters, at that time when he shall come in his own proper person, and men shall see him as he is in reality, what machinations and deceits and delusions will he not bring into play, with the purpose of seducing all men, and leading them off from the way of truth, and from the gate of the kingdom?
Source: The End of the World (Pseudonymous) (New Advent)