Final answer:
Elie's mentor in the mystical sect of the Jewish faith, as described in Elie Wiesel's book 'Night', was Moishe the Beadle.
Step-by-step explanation:
The answer to the question, "Who was Elie's mentor in this mystical sect of the Jewish faith?" is not directly present in the provided reference information. However, the context of the question suggests that it relates to Elie Wiesel, the author of Night, and his experiences as described in that book. In Night, Elie's mentor is Moishe the Beadle, who taught him about the Kabbalah and Jewish mysticism before the deportation of the Jews from Sighet during World War II.