I would also recommend the ORIGINAL, unabridged, prayer to St. Michael from Pope Leo XIII.
He reportedly composed it in response to a vision he had of Our Lord and Satan discussing the future of the Church, and the vision left him pale and apparently lifeless, to the point that he appeared to those around him to have expired.
And it included this --
Where the See of the Blessed Peter and the Chair of Truth have been set up for the light of the gentiles, there they have placed the throne of the abomination of their wickedness, so that, the Pastor having been struck, they may also be able to scatter the flock.
He foresaw a strike against the Papacy and the replacement of St. Peter's throne with their own.
[This is not necessarily pointing to sedevacantism, just a taking over of the Papacy by the forces of evil.]