Theologian and Cardinal
He points out that the famous axiom "Ubi Petrus, ibi Ecclesia" (Where the Pope is, there is also the Church) holds true only when the Pope acts and behaves as the Pope, because Peter "is subject to the duties of the Office" otherwise, "neither is the Church in him, nor is he in the Church."
Jerome: I suppose the gates of hell to mean vice and sin, or at least the doctrines of heretics by which men are ensnared and drawn into hell.
Origen: But in heavenly things every spiritual sin is a gate of hell, to which are opposed the gates of righteousness.
Raban.: The gates of hell are the torments and promises of the persecutors. Also, the evil works of the unbelievers, and vain conversation, are gates of hell, because they shew the path of destruction.
Origen: Wherefore if we, by the revelation of our Father who is in heaven, shall confess that Jesus Christ is the Son of God, having also our conversation in heaven, to us also shall be said, "Thou art Peter;" for every one is a Rock who is an imitator of Christ. But against whomsoever the gates of hell prevail, he is neither to be called a rock upon which Christ builds His Church; neither a Church, or part of the Church, which Christ builds upon a rock.
Bergoglio is a heretic therefore he can not be a legitimate pope but a usurper because otherwise the gates of hell would have prevailed.