To E M,
Identifying "the Beast" as the antichrist as referenced in the Book of Apocalypse, it seems clear antichrist comes prior to the period of peace and the Triumph of the Immaculate Heart (unless you can point out my error!):
"Have unreserved confidence in my Immaculate Heart! Believe that I am able to do everything with my Son. Substitute my Immaculate Heart in place of your sinful hearts. Then it will be I who will draw the power of God, and the love of the Father will renew the fullness of Christ in you. Fulfill my request so that Christ may reign as the King of Peace."
"The world will have to drain the cup of wrath to the dregs because of the countless sins through which His Heart is offended. The Star of the infernal regions will rage more violently than ever and will cause frightful destruction, because he knows that his time is short, and because he sees that already many have gathered around my sign. Over these he has no spiritual power, although he will kill the bodies of many; but through these sacrifices, my power to lead the remnant host to victory will increase."
"In secret I shall work marvels in souls until the required number of victim souls will be filled. Upon you it depends to shorten the days of darkness. Your blood and your sacrifices shall destroy the image of the beast. Then I can manifest myself to the world for the glory of the Almighty. Choose my Sign, so that the Triune God may soon be adored and honored." - Our Lady of Marienfried
"Now is the time; the abyss is opening. Here is the King of Kings of darkness, here is the Beast with his subjects, calling himself the Saviour of the world. He will rise proudly into the air to go to Heaven. He will be smothered by the breath of the Archangel Saint Michael. He will fall, and the earth, which will have been in a continuous series of evolutions for three days, will open up its fiery bowels; and he will have plunged for all eternity with all his followers into the everlasting chasms of hell. And then water and fire will purge the earth and consume all the works of men's pride and all will be renewed. God will be served and glorified." - Our Lady of La Salette