Who is Christopher from No Longer at Ease and what is their importance?

Christopher is a friend of Obi Okonkwo, Christopher has a degree from the London School of Economics and has recently transferred to Lagos from Enugu. Christopher always takes the opposite side from Obi in any argument. A ladies' man, Christopher introduces Obi to an Irish girl teaching in a Roman Catholic convent, and argues against his marrying Clara Okeke because she is an osu.