The seven deadly sins

Meliodas is a emotionless boy. He was sent to school to learn emotions or at least understand them. He is strong and intelligent.

What happen when 6 people create a group and tests Meliodas if he is good enough for them? Let's just say that he uses a fake name. And what is it with Elizabeth? The one Meliodas saved from getting to the nurse office before the school even started.