He uses the title Vicarius Christi, meaning the vicar of Christ.
882 The Pope, Bishop of Rome and Peter’s successor, “is the perpetual and visible source and foundation of the unity both of the bishops and of the whole company of the faithful.”402 “For the Roman Pontiff, by reason of his office as Vicar of Christ, and as pastor of the entire Church has full, supreme, and universal power over the whole Church, a power which he can always exercise unhindered.”403 – Catechism of the Catholic Church – Part one Section two Chapter three Article 9 Paragraph 4.
Vicar and Anti
The English word “vicar” root and origin is the Latin word Vicarius meaning substitute or deputy.
Greek Original Word: ἀντί
Part of Speech: Preposition
Phonetic Spelling: (an-tee’)
Short Definition: instead of, for
Definition: (a) instead of, in return for, over against, opposite, in exchange for, as a substitute for, (b) on my behalf, (c) wherefore, because.
Anti and vicar have the same meaning. Thus, Vicar of Christ and Antichrist are exactly the same by definition just different languages.