St. Louis Grignion de Montfort is the author of the famous True Devotion to the Blessed Virgin, one of the Marian works par excellence in Church history.
Beyond the devotional aspects, this saint prophetically narrates how the opposition between the devil and the Virgin Mary will be exacerbated at the end of time and how Our Lady will help Christians by distributing special graces in the midst of persecution of the Church.
Thus, St. Louis de Montfort revealed how the Virgin will help Christians at the end of time
St. Louis de Montfort relates that towards the end of time, "the devil, knowing that he has little time left -much less than ever- to lose people, will redouble his efforts and attacks every day. In fact, he will shortly provoke cruel persecutions and set up terrible ambushes for the faithful servants and true children of Mary, whom he finds much more difficult to defeat than the others."
However, in the midst of tribulation, "the humble Mary will always triumph over that proud man, and with such a complete victory that she will crush his head, where his pride resides. (…) She will vanquish his diabolical plans and will defend her servants from those deadly claws until the end."
"Mary's power over all the demons," describes St. Louis Grignion de Montfort "will shine, however, in a particular way in recent times, when Satan will lay snares on her heel, that is, on her humble servants and poor children whom she will raise up to make war on him."
Then Christians “will be small and poor in the world's judgment; humiliated in front of everyone, (...) but, instead, they will be rich in graces and charisms, which Mary will distribute abundantly; great and elevated in holiness before God; superior to any other creature by their burning zeal; and so strongly supported in divine help, that with the humility of their heel and united to Mary, they will crush the head of the devil and make Jesus Christ triumph."