Who was the final Apostle?!
Question: On whom did he pass his authority?
Answers: On whom did he pass his authority?
If you mean the final one chosen of the Twelve Apostles, it would be Matthias, who was chosen to replace the traitor, Judas Iscariot.
Paul of Tarsus could also be called the "Final Apostle", having been chosen by Jesus himself to be an Apostle. Since the original Twelve had all been selected by Jesus personally, it does fit that Judas' replacement would, likewise, be chosen by Him as well.
However, the Roman Catholic Church lists the Twelve Apostles as including Matthias, not Paul.