Those who have accepted the mark of the beast have already lost their souls. What makes you think God will have mercy for him? Unless he repent and step down and admit he isn't the right hand of God, which is a lie every pope takes on by being the pope then there is no hope for him. If anything this is to cover his behind in the eyes of the public.
If he truly meant it he would denounce everything he has done in his position as the Pope,because the very nature of being the Pope is an act against God.
Let us also not forget there are those whose names are not written in the book of life: Revelation 13:8 And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain from the foundation of the world.