Is Caravaggio an unnecessary character

Is Caravaggio an unnecessary character？
   In the book, there is a part about a man whose name is Caravaggio with broken figures and who wanted to revenge. Many people doubted if the existence of this character was necessary because he belonged to another plot, they said.

     Having a war needs to play trick all the time. Intelligence is half way to success. Many people discarded their own names, changed their identities, and forgot their true selves. Some sacrificed themselves for the nation's benefits. That’s what this man did.

    He was a Canadian spy in North Arica served for Allied Forces. In 1942, he was ordered to stay in Tobruk when Germany Army occupied Cairo. Then his identity was busted. Germany tortured him in order to know the name list of all the intelligence personnel in North Africa, but he showed his loyalty by the cost of losing his thumbs of both hands.

    Then, he started to look for the one who he thought betrayed him. Finally, he found the patient who might be the one who betrayed him. He tried everything in brutal way to make the patient telling the truth. After all the effort he did, the patient believed and admitted that he killed Katharine even though he did not.

    Caravaggio is a lonely and selfish man, but it was not his fault. It was the war's fault.  War, the devil must be spitted, deprived every hope and dream we ever had such as love, loyalty and trust. What will we get from the war? My answer is - nothing. The man with broken figures is just a symbol of the result of the war, a character whose life was gone, a sacrifice of the war. He could only live with hating others. But the trauma that the war brought to the people takes some time to fix.