The main theme of "Night" by Elie Wiesel is the prevalence of religious faith. This theme is developed by the actions of Eliezer who struggles to keep his faith in God.
We can arrive at this answer because:
Eliezer grew up within the Jewish religion and was taught to believe in a kind and benevolent God.
This belief is the basis for Eliezer's faith, which made him believe that God would never forsake him.
however, during World War II and after suffering a lot in a concentration camp along with other Jews, Eliezer had his faith shaken.
He began to question whether God was kind and benevolent, as he looked like all Jews were helpless.
At the same time, Eliezer only had the religion and belief in God to cling to, but it was very difficult to maintain faith amid suffering.
More information on the theme of a text at the link:
as for a disadvantage I would say they can be killed by white oak stake and they watch everyone who they love die around them because they live forever
