Who is Cletus from Girls at War, and Other Stories and what is their importance?

Cletus is a bombastic soldier in the war for Nigerian independence. Entering military life, he cannot adapt to life without sugar. One day, he secures a packet of artificial sweetener, but it is so bitter that Cletus ends up vomiting. He goes to a Father Doherty, who is supposed to be able to secure anything. When Cletus and his friend Mike go to him, Doherty goes mad at the sugar request. He attacks Cletus, shouting that people are dying in the war. One day, Mike is assigned to make a sojourn to the island of Sao Tome, where he secures a bag of sugar cubes for Cletus. Cletus invites his girlfriend Mercy to join him, and when she sees the sugar she takes a handful of it. Cletus goes mad, throwing her out and declaring that he sees her true face now.