One thing I have learned in dealing with Catholics is to not discount the most absurd things they've been known to say because Catholic's beliefs are all over the map.
So when a Catholic says the pope saves souls, after seeing all the argument from Catholics about apostolic succession and retaining and remitting sins, nothing is impossible to believe from a Catholic.
Besides, why shouldn't they believe that the pope can save souls. Official Catholic doctrine holds that Mary can.
http://www.vatican.va/archive/ENG0015/__P2C.HTM
966 "Finally the Immaculate Virgin, preserved free from all stain of original sin, when the course of her earthly life was finished, was taken up body and soul into heavenly glory, and exalted by the Lord as Queen over all things, so that she might be the more fully conformed to her Son, the Lord of lords and conqueror of sin and death."506
The Assumption of the Blessed Virgin is a singular participation in her Son's Resurrection and an anticipation of the resurrection of other Christians:
In giving birth you kept your virginity; in your Dormition you did not leave the world, O Mother of God, but were joined to the source of Life. You conceived the living God and, by your prayers, will deliver our souls from death.507
. . . she is our Mother in the order of grace
CC 2853: "Victory over the 'prince of this world' [Jn 14:30] was won once for all at the Hour when Jesus freely gave himself up to death to give us his life. This is the judgment of this world, and the prince of this world is 'cast out.'[Jn 12:31; Rev 12:10.] 'He pursued the woman' [Rev 12:13-16.] but had no hold on her: the new Eve, 'full of grace' of the Holy Spirit, is preserved from sin and the corruption of death (the Immaculate Conception and the Assumption of the Most Holy Mother of God, Mary, ever virgin). 'Then the dragon was angry with the woman, and went off to make war on the rest of her offspring.' [Rev 12:17.] Therefore the Spirit and the Church pray: 'Come, Lord Jesus,' [Rev 22:17,20.] since his coming will deliver us from the Evil One."
YET here it is written in Romans
Romans 3 New International Version (NIV)
(20) Therefore no one will be declared righteous in God’s sight by the works of the law; rather, through the law we become conscious of our sin.
Righteousness Through Faith
(21) But now apart from the law the righteousness of God has been made known, to which the Law and the Prophets testify. 22 This righteousness is given through faith in[h] Jesus Christ to all who believe. There is no difference between Jew and Gentile, 23 for all have sinned and fall short of the glory of God,
24 and all are justified freely by his grace through the redemption that came by Christ Jesus.
23 For all have sinned, and come short of the glory of God;
24 Being justified freely by his grace through the redemption that is in Christ Jesus: (KJV)
It does NOT say: "For all EXCEPT MOTHER MARY and come short of the glory of God."
In giving birth you kept your virginity; in your Dormition you did not leave the world, O Mother of God, but were joined to the source of Life. You conceived the living God and, by your prayers, will deliver our souls from death.507
>>This is a Christological reference dating back to St. Irenaeus of Lyons in the 2nd Century.
“In accordance with this design, Mary the Virgin is found obedient, saying, ‘Behold the handmaid of the Lord; be it unto me according to thy word.’ But Eve was disobedient; for she did not obey when as yet she was a virgin. And even as she, having indeed a husband, Adam, but being nevertheless as yet a virgin (for in Paradise ‘they were both naked, and were not ashamed,’ inasmuch as they, having been created a short time previously, had no understanding of the procreation of children: for it was necessary that they should first come to adult age, and then multiply from that time onward), having become disobedient, was made the cause of death, both to herself and to the entire human race; so also did Mary, having a man betrothed [to her], and being nevertheless a virgin, by yielding obedience, become the cause of salvation, both to herself and the whole human race. And on this account does the law term a woman betrothed to a man, the wife of him who had betrothed her, although she was as yet a virgin; thus indicating the back-reference from Mary to Eve, because what is joined together could not otherwise be put asunder than by inversion of the process by which these bonds of union had arisen; s so that the former ties be cancelled by the latter, that the latter may set the former again at liberty. And it has, in fact, happened that the first compact looses from the second tie, but that the second tie takes the position of the first which has been cancelled. For this reason did the Lord declare that the first should in truth be last, and the last first. And the prophet, too, indicates the same, saying, “instead of fathers, children have been born unto thee.’ For the Lord, having been born “the First-begotten of the dead,’ and receiving into His bosom the ancient fathers, has regenerated them into the life of God, He having been made Himself the beginning of those that live, as Adam became the beginning of those who die. Wherefore also Luke, commencing the genealogy with the Lord, carried it back to Adam, indicating that it was He who regenerated them into the Gospel of life, and not they Him. And thus also it was that the knot of Eve’s disobedience was loosed by the obedience of Mary. For what the virgin Eve had bound fast through unbelief, this did the virgin Mary set free through faith.”
Irenaeus,Against Heresies,3:22(A.D. 180),in ANF,I:455
But considering that you divide Jesus into two persons and reject the Hypostatic Union, I’m sure this goes over your head.