What did Eliezers determination to remain with his father reveal in night?

He remains loyal to his father if you mean he doesn't leave him for death. When Elie's father gets sick, Elie is by his side pretty much at all times. At first he helps him, but later on when his father is asking for water, (which was bad for him) Elie accepts the fact that his father is dying. He starts to appease his father which makes it worse. Ultimately in the end, Elie's father dies from the sickness.