Matter of fact, any Catholic priest, not only the Pope is a vicar of Christ as he acts in the person of Christ when offering the sacrifice of the Mass (”do it in memory of me”). The “vicar of Christ” is one of the traditional titles of the Pope, of course, but once we are into analysis of what it means, here you go.
Being an ex-Catholic, I know where you are coming from. But History is a great teachers if one only takes the time to learn from it, which I do the best I can to learn the truth it contains. I take it you are not all that aquainted with history. Up to the end of the fourth century the popes called themselves "vicars of Peter", but since the fifth century, "vicars of Christ". The name "pope" (papa) or "father", was in AD 500 "appropriatd to the Roman pontiff, it having formally been the title of all bishops alike" (Gibbon, vii, i., page 37). That title, which you apply to all "priests" also, was given by a Roman Council to Gelasius, Bishop of Rome in the 5th century: "We behold in thee Chirst's vicar" (Hardouin, ii., 946-947).
Cardinal Bellarmine, in his Treatise on the Roman Pontiff (De Rom. Pont. Lib. ii. Ch. XXXI., Ingoldstadt, 1839), said: "Pope: Father of Fathers; the Pontiff of Christians, High Priest, the Vicar of Christ, the Head of the Body, that is of the Church, the foundation of the building of the Church; the Father and Doctor of the faithful; the Ruler of the House of God; the Keeper of God's Vineyard; the Bridegroom of the Church; the Ruler of the Apostolic See; the Universal Bishop." And in his "De Conciliorum Auctoritate Lib. ii., ch. XVII." "All the names which are given in the Scriptures to Christ (where it appears that He is superior to the Church) - all these names are given to the Pope."
What more do you want me to say? This is so far from being what was taught in the beginning of the church that it is nothing but the pride of mortal men to bring glory and power to themselves. All Christians should be preaching the good news of Christ, not a church. It is Christ that saves, not an organization.
Christ said to "do this in memory of Me."
Not "do this pretending to be Me."
Therefore no one "acts in the person of Christ." No one is "another Christ." There is only one Savior, King and Redeemer, Jesus Christ, and his substitutionary atonement for His sheep is complete. God has accepted Christ's sacrifice, attributing His righteousness to our account and His death as satisfaction for our sins. Therefore our sins have been forgiven and there is no more offering for sin.
From henceforth expecting till his enemies be made his footstool. For by one offering he hath perfected for ever them that are sanctified. Whereof the Holy Ghost also is a witness to us: for after that he had said before, This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them; And their sins and iniquities will I remember no more. Now where remission of these is, there is no more offering for sin." -- Hebrews 10:12-18"But this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God;