Battle of the brains

Exploration Stage: Compartment No.8
From: Roger Doubledeal
Description: I believe that the person who sent the black cat to me was the one who was known as the "Invincible Grandmaster". I beat him at chess and took away his title of "Grandmaster". He was outraged and tried to kill me with the trophy I had won. Here, look at this. You see how the horns are chipped off from the impact of that?
Completed: See, you know I am not lying. It means that I hit him so hard that he chipped a corner. But in the end he apologized to me. I was given a small reimbursement for the physical and emotional trauma, and I forgave him.